UNIVERSITY OF APPLIED SCIENCES
Department of Conservation
CHEMICAL SUBSTANCES IN MUSEUM COLLECTIONS: THE DECISION-MAKING
PROCESS IN THE CONSERVATION OF CHEMICAL SUBSTANCES AT THE POLICE
MUSEUM IN TAMPERE
Elzbieta Djupsjöbacka
Textile Conservation
Master’s Thesis
May 2008
ABSTRACT
UNIVERSITY OF APPLIED SCIENCES
Degree Programme:
Major:
Master’s Thesis:
Author:
Year:
Pages:
Conservation
Textile Conservation
Chemical substances in museum collections: The decisionmaking process in the conservation of chemical substances at
the Police Museum in Tampere.
Elzbieta Djupsjöbacka
2008
107 +17
The conservation of chemical substances from the collection of the Police Museum in
Tampere inspired the studies presented in this thesis. The studies focused on three central
issues in the conservation of chemical substances as part of a museum collection: the
ethical and practical decisions regarding the preservation of difficult objects, the analysis
and identification of said substances, and finally their practical conservation. The thesis is
hence divided into three parts according to these issues, answering the questions “Why?”,
“What?”, and “How?”.
The first part, entitled “Why?” discusses the need for preserving chemical substances even
when they can prove hazardous to either staff or the rest of museum collection. The
necessity of preserving the integrity of the object by saving not only the container, but also
the chemical is discussed.
The second part “What?” takes a look at the various chemicals that may be encountered
as part of museum collections. Identification of these chemicals is a key to correct
decision-making. Some methods of identification and analysis are described in this
section. As a practical example, the identification process of the chemicals at the Police
Museum is described in detail.
The third part of the thesis presents general guidelines for how the preservation of
chemicals should be undertaken and what aspects of active and preventive conservation
should be considered, in particular when deciding on a storage or disposal plan for the
substances. It provides some common standards that should be maintained when
conserving chemical substances. In addition, this section contains examples of museums
tasked with preserving chemical substances and brief descriptions of their solutions to the
unique problems of this endeavour.
Keywords: chemical substances, identification of chemicals, museum collection of
chemicals, hazardous chemicals in museum, disposal of chemical substances
MUOTOILUINSTITUUTTI
Koulutusohjelma:
Suuntautumisvaihtoehto:
Opinnäytetyön nimi:
Tekijä:
Vuosi:
Sivuja:
TIIVISTELMÄ
Konservointi
Ylempi ammattikorkeakoulututkinto, Tekstiilikonservointi
Kemialliset aineet museokokoelmissa: Kemiallisten aineiden
konservointiin liittyvä päätöksentekoprosessi Tampereen
Poliisimuseossa.
Elzbieta Djupsjöbacka
2008
107 + 17
Tampereen Poliisimuseon kokoelmien kemiallisten aineiden konservointiin liittyvien ratkaisujen tekeminen johti asian tutkimiseen laajemmasta näkökulmasta ja toimii pohjana tälle
tutkielmalle. Kemiallisten aineiden konservointia osana museokokoelmia lähestytään
kolmesta näkökulmasta: hankalien aineiden säilyttämiseen liittyvät eettiset ja
käytännölliset ongelmat, aineiden analysointi ja tunnistaminen sekä niiden konservointi
käytännössä. Tutkielma on sen perusteella jaettu kolmeen osaan pyrkien vastaamaan
kysymyksiin ”Miksi?”, ”Mitä?” ja ”Miten?”.
Ensimmäisessä osassa, ”Miksi?”, keskustellaan kemiallisten aineiden säilyttämisen syistä,
vaikka aineet voivatkin olla vaarallisia museon henkilökunnalle tai museon muille esineille.
Luvussa käsitellään myös esineiden säilyttämistä kokonaisuuksina, ei pelkästään astian
vaan myös sisällön tallettamisen merkitystä.
Tutkielman toinen osa, ”Mitä?”, käsittelee erilaisia kemiallisia aineita, joita museoiden kokoelmissa voidaan kohdata. Näiden aineiden tunnistaminen on välttämätöntä oikeiden
konservointipäätösten tekemiseksi. Luvussa esitellään joitakin analysointimenetelmiä, joita
museoissa voidaan käyttää aineiden tunnistamisessa. Käytännön esimerkkinä esitellään
Tampereen Poliisimuseon kemiallisten aineiden tunnistusprosessi.
Kolmannessa osassa, ”Miten?”, esitellään yleiset ohjeet kemiallisten aineiden säilyttämiseen ja mitä aktiivisia ja säilyttäviä konservointimenetelmiä voidaan käyttää. Luvussa
käsitellään myös aineiden varastoimiseen ja hävittämiseen liittyvää päätöksentekoa.
Tutkielmaa varten kerättiin kyselytutkimuksella tietoa kemiallisten aineiden säilyttämisestä
ja konservoinnista useissa museoissa maailmalla ja saatuja vastauksia käytetään
esimerkkeinä tässä luvussa.
Avainsanoja: kemialliset aineet, kemialliset aineiden tunnistaminen, kemialliset aineet museokokoelmissa, vaaralliset kemikaalit museossa, kemiallisten aineiden hävittäminen.
Table of contents
1. Why should we consider chemical substances worthy of historical
preservation? ..................................................................................................................... 1
1.1. Introduction ........................................................................................................... 1
1.2. Museum object as a cult object ............................................................................. 2
1.3. Can chemicals and other difficult substances be classified as historical objects? . 3
1.3.1. Chemical substances as archaeological objects ............................................ 4
1.3.2. Chemical substances as antiquities ............................................................... 5
1.3.3. Chemical substances as historic works.......................................................... 5
1.3.4. Chemical substances as heritage and cultural heritage ................................. 6
1.3.5. Chemical substances as conservation objects ............................................... 6
1.4. Chemical substances as an aspect of professional ethics .................................... 8
2. What kinds of chemical substances are encountered as historical objects?..... 10
2.1. Classification of chemical substances ................................................................. 11
2.1.1. Organic and inorganic substances ............................................................... 11
2.1.2. Solids and liquids ......................................................................................... 12
2.1.3. Acids, bases and neutral substances ........................................................... 13
2.1.3.1
Acids ..................................................................................................... 13
2.1.3.2.
Bases .................................................................................................... 14
2.1.4. Toxic, dangerous and non-hazardous substances....................................... 14
2.1.4.1.
Hazardous substances ......................................................................... 14
2.1.4.2.
Toxic substances .................................................................................. 15
2.1.4.3.
Non-hazardous substances .................................................................. 17
2.2. Ageing process ................................................................................................... 17
2.3. Changes in the physical properties of chemical substances ............................... 20
2.3.1. Changes in the state of matter ..................................................................... 20
2.3.2. Hygroscopic properties and reactions with water ......................................... 23
2.3.3. Sedimentation and separation of chemical substances ............................... 24
2.4. Changes in chemical properties .......................................................................... 25
2.4.1. Oxidation reaction ........................................................................................ 25
2.4.2. Changes in colour ........................................................................................ 26
2.4.3. Changes in odour ......................................................................................... 27
2.4.4. Precipitation...................................................................................................... 28
2.4.5. Predicting chemical changes ............................................................................ 28
2.5. Effects of mould growth on chemicals in museum collections ............................. 29
2.6. Researching physical and chemical properties ................................................... 31
2.6.1. Sampling ...................................................................................................... 33
2.6.2. FTIR spectroscopy ....................................................................................... 35
2.6.3. NIR - Near Infrared Spectroscopy ................................................................ 36
2.6.4. X-Ray Fluorescence Spectroscopy .............................................................. 36
2.6.5. X-ray Absorption Near Edge Structure (XANES) ......................................... 37
2.6.6. Raman spectroscopy ................................................................................... 37
2.6.7. Laser methods ............................................................................................. 38
2.6.8. Chromatography methods............................................................................ 38
2.7. Molecular Diversity Preservation International .................................................... 39
2.8. Documentation of chemical substances in a museum ........................................ 39
3.
Chemicals in the Police Museum collection in Tampere, Finland ....................... 40
3.1. Where do they come from? .................................................................................... 40
3.2. Present condition and storage of chemicals at the Police Museum in Tampere .... 42
3.3. Types of chemicals in the collection of the Police Museum in Tampere and their
characteristic. ................................................................................................................. 45
3.4. Identification of chemicals from the collection of the Police Museum in Tampere46
3.4.1. Description of conservation objects ............................................................. 46
3.4.2. FTIR spectroscopy ....................................................................................... 55
3.4.3. pH measurement ......................................................................................... 70
3.4.4. X-Ray Fluorescence Spectroscopy .............................................................. 71
3.4.5. Smell ............................................................................................................ 73
3.4.6. Interpretation of research results ................................................................. 74
3.5. Active and preventive conservation of chemicals from the Police Museum in
Tampere ........................................................................................................................ 74
3.6. Literature research of chemical and physical behaviours of chemicals the from
Police Museum .............................................................................................................. 75
3.7. Decision-making.................................................................................................. 76
3.7.1. Disposal ....................................................................................................... 78
3.7.2. Storage ........................................................................................................ 78
4. How to preserve chemicals in museum collections.............................................. 80
4.1. Preventive conservation of chemical substances in a museum .......................... 80
4.2. Standards for collecting and preserving chemicals ............................................. 81
4.2.1. Legal possession of chemicals .................................................................... 81
4.2.2. Safety of the museum .................................................................................. 82
4.2.2.1. Health and Safety Policy concerning collection of chemicals ..................... 83
4.2.3. Disposal of chemical substances ..................................................................... 84
4.3. Advice on the preservation of chemicals ............................................................. 85
4.3.1. Active conservation of chemicals ................................................................. 85
4.3.2. Preventive conservation of chemicals .......................................................... 86
4.3.2.1.
Screw-top containers ............................................................................ 87
4.3.2.2.
Ground glass jars .................................................................................. 88
4.3.2.3
Bail-top containers ................................................................................ 89
4.3.2.4.
Metal lids ............................................................................................... 89
4.3.2.5.
Bakelite resin lids .................................................................................. 89
4.3.2.6.
Double-container system ...................................................................... 90
4.4. How chemicals are preserved in museums – a survey ....................................... 91
5. Conclusions .............................................................................................................. 98
References ..................................................................................................................... 100
Table of Figures ............................................................................................................. 105
Table of Photos.............................................................................................................. 106
Table of Tables .............................................................................................................. 107
Appendix 1. European hazard symbols......................................................................... A1-1
Appendix 2. Common hazard symbols.......................................................................... A2-1
Appendix 3. IR spectra of chemicals from the collection of the Police Museum in Tampere
and their analysis............................................................................................................ A3-1
Appendix 4. Characteristic IR Absorption ..................................................................... A4-1
Acknowledgments:
The author of this thesis would like to thank Tiina Tuulosvaara-Kaleva, the curator of the
Police Museum in Tampere, for her friendly attitude and for allowing me to complete my
studies on the collection of chemicals in their museum.
Many thanks to my professional colleagues who answered my inquiries and shared their
experience concerning collections of chemicals: Jos Breukers, conservator from the
Nederlands Politiemuseum; Anna Ridley, assistant curator of the Justice & Police Museum
in Sydney; Anna Chan, assistant curator of the Hong Kong Science Museum; Henna
Sinisalo, curator of the Helsinki university Museum
Arppeanum; Lee Ann Obos ,
Pharmaceutics Laboratory Instructor, Throop Pharmacy Museum Curator, Albany College
of Pharmacy; Briony Hudson, Keeper of the Museum Collections, Royal Pharmaceutical
Society of Great Britain; Elisabeth Huwer, Director of Deutsches Apotheken-Museum.
Finally I would like to thank Ulla Knuutinen, Principal Lecturer at EVTEK University of
Applied Science for her support, advice and for completing the demanding task of reading
and correcting my thesis.
1. Why should we consider chemical substances worthy of historical
preservation?
1.1. Introduction
Museums’ collections worldwide may contain very different objects and substances
that all are a part of our heritage. Museums may have many problems with their
collections, and not only the usual ones like financial and logistical but also ethical
and professional that concern artefacts that are unusual, need special storage, or are
dangerous to other objects in the collections or to people.
The Museum of Hemingway has a collection of particularly unique objects. The
Museum of Hemingway is situated in the writer’s home in Key West (Florida, USA). It
has a problem with six-toed cats that are descended from a cat owned by
Hemingway. They are interesting as animals and have become an integral part of the
museum, but can they be considered a cultural heritage and preserved? The
presence of live museum objects requires a special licence from the U.S. Department
of Agriculture. (National Geographic 2007, p.5)
In this part of my thesis I will discuss the ethical problems that concern chemical
substances in museum collections. Chemical substances in museum collections may
not present the same dilemmas as six-toed cats, but they may also cause many
problems relating to their preservation, storage, and ethical considerations.
Most pharmaceutical museums include chemical substances and medicines in their
collecting programmes. There the chemicals were collected in order to study and
preserve the history of medicine. In other museums chemicals might only be a part of
the collection like cosmetics, laboratory reagents, dental and veterinary preparations,
dyes, germicides and pesticides. Sometimes these materials are parts of other
objects that are collected by the museum. Chemical substances may pose a health
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hazard to people, or cause a risk to the rest of the collection. They also tend to be a
focus for irrational concerns of the museum staff.
Chemicals and other “strange” or unknown substances in museums can prove to be a
big challenge for a conservator. There are many difficulties and problems with their
conservation, preservation and storage. The difficulties and problems are not only
connected to physical and chemical matters but also ethical and moral issues. These
issues should be discussed and understood by conservators. They should be
acknowledged and used in their decision-making process.
“One should make sure at the very outset that there is a truly philosophic basic so
that conservators shall not only be good practitioners, but scholars as well, knowing
not only what they do, but why they do it.” (Stout 1945, p 37).
There are many definitions to describe conservation objects, but how should
chemicals and substances like food, cosmetics, or medicines be categorized? What
discipline of specialist conservators should take care of them? Do they fit the
description of artefacts that belong to our heritage? Should they be preserved, and if
so, why should they be preserved?
“We really have only three alternatives in dealing with an existing historic resource:
we can keep it, we can change it, or we can destroy it. “ (McGilvray 1988, pp. 3-17).
In this section I will try to answer the above-mentioned questions drawing on theories
and concepts present in contemporary conservation and discuss which of the
alternatives McGilvray describes should be chosen when dealing with chemical
substances in museums.
1.2. Museum object as a cult object
For most museum visitors the most important part of the experience is to see the real
historical object. In our age of communication and worldwide access to the Internet,
3
where images of museum objects can be viewed, people visit museums to see them
in reality.
Why is it so important for us to see the original object enclosed in a museum cabinet?
Why do copies placed in museums tend to be disappointing to visitors even if they are
equally effective at presenting the historical information?
Outi Peisa, the curator of Helsinki City Museum speaks about an “object’s energy” –
the information and feelings that the museum’s object awakens in a viewer. This
“energy”, however immaterial, tends to provoke the thoughts and emotions that draw
us to museums, to see the real object rather than replicas or images.
Tusquet writes that in many cases a copy may offer a more complete experience than
the authentic object, which may be significantly damaged, but most people still prefer
to view the original object rather than the copy, regardless of its quality. (Vinas 2005,
pp 31-41).
The authentic object with its aura, energy or feeling of nostalgia provides more
excitement than replicas. That feeling and the need for authenticity should be taken
into consideration when making decisions about the preservation of chemicals or
other “strange” objects.
1.3. Can chemicals and other difficult substances be classified as historical objects?
Many terms are used to describe objects that are valued as historical and need to be
preserved. They can be named antiquities, cultural property, historic objects,
archaeological objects, and heritage. (Vinas S.M., 2005).
The definitions of these terms are various and confusing. What objects should we
preserve? What criteria should they fulfil? Into what category do chemical substances
fall? In his book Vinas presents several definitions commonly used to describe
conservation objects. Which of the definitions would best fit objects like chemicals
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and perishables? The correct definition may be difficult to find when there are
problems even describing the category for chemical substances.
Usually when speaking about chemicals we visualize chemicals used in a laboratory,
stored in well-labelled bottles or boxes and relatively new. Their chemical content is
usually the same as the chemicals used in modern laboratories. Do they possess
historical value? Is their preservation necessary?
Most conservators would probably decide to dispose of chemicals because of their
potential danger to the rest of the collection, and preserve only their packaging as of
historical value. Some chemicals however, like for example pure natron salt (sodium
carbonate (Na2CO3.10H20)), a well known mineral found at an archaeological site and
that was used in ancient Egypt for mummification, can be considered as
archaeological objects and preserved in museums.
The problem is complicated by the fact that chemicals age and their content may
change. Are they then a source of reliable historical information?
Below, chemicals and other “strange” substances are discussed according to
categorization of museum objects proposed by Vinas. (Vinas 2005, pp 31-41).
1.3.1. Chemical substances as archaeological objects
During archaeological excavation some chemicals, medicines, foodstuffs or traces of
them can be found. The substances that are found in archaeological excavations can
be called archaeological objects. According to Johnson, archaeological objects are
not only the objects and samples recovered during excavation but also records
produced by the archaeologist at work. (Johnson 1993).
Usually there only minute amounts of chemicals, sometimes just traces which cannot
be preserved for museums as objects but which can only be tested for the historical
information that they contain.
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What about objects from not so far in the past? They may also become
archaeological objects some day and be a source of historical information. Vinas
gives an example of a contemporary bottle of beer that can probably give future
historians more information about our civilization than some contemporary pieces of
art. Many conservators would be tempted to dispose of the beer and preserve only
the bottle. (Vinas 2005, p.34)
1.3.2. Chemical substances as antiquities
Antiquities are considered objects that have become obsolete. This is mostly true and
can be an adequate name to describe chemical substances in museums. The word
antique and antiquity, however, is more connected to objects that also have some
artistic value, and not many antiquarians would consider a bottle of aniline from 1952
(artefact from the Police Museum in Tampere) used by the Traffic and Road Police for
testing the purity of Diesel oil an antique. On the other hand, some might describe a
bottle of wine from that year as an antique object.
1.3.3. Chemical substances as historic works
Historic works are objects that are useful to historians. They provide historical
knowledge or evidence. Chemicals and other “strange” substances may fit this
definition of a historical object very well, as objects that are worthy of preserving
because they contain historical information.
This definition of historic work is very broad and on its borders can be placed a
medicine case containing bottles of mixtures and herbs from the Middle Ages, but
also a bottle of Coca-Cola from the 1950s whose value is greater for collectors than
for historians.
A museum object has value only when it can provide historical information. According
to this, removing part of the object, like for example disposing of a chemical and
preserving only its package, decreases its historical value. Disposing of the chemical
6
removes some of the information and integrity of the object. A decision about
disposing of the chemical should be made cautiously and only if the chemical is
hazardous to store.
1.3.4. Chemical substances as heritage and cultural heritage
Cultural heritage ("national heritage" or just "heritage") is the legacy of physical
artefacts and intangible attributes of a group or society that are inherited from past
generations, maintained in the present, and bestowed for the benefit of future
generations. Often, what is considered cultural heritage by one generation may be
rejected by the next, to be revived again by a succeeding one.
We can place chemical substances within this definition. If anything that is transmitted
from the past belongs to our heritage then even chemicals that are relatively new and
do not have historically valuable information can be considered objects of cultural
heritage.
1.3.5. Chemical substances as conservation objects
The definition of a conservation object is not precise. The decision about conserving
and preserving one object and not conserving another is always made by museum
professionals on the basis of their knowledge and intuition. All of the above definitions
of museum objects can be used, but they do not fully describe a conservation object.
This fact may be directly linked to the difficulties conservators face when deciding
whether to conserve an object or not. (Leigh 1994, pp. 269 - 286).
If there is no definition regarding what should be preserved and conserved, then the
responsibility will have to be shouldered by museum professionals and conservators.
Bonsanti says that conservation is made up of technical, methodological, scientific,
and professional factors, as well as an attitude describing the conservators personal
and emotional relationship to the object they work on. (Bonsanti 1997, pp 109 - 112).
7
This attitude or intuition is difficult to trust, yet essential when deciding upon
conservation procedures.
From the middle of the 20th century, conservation can be considered scientific
conservation because of the use of hard science in the conservation process.
Conservators base their work on science, yet there will always remain aspects of their
work which require them to be comfortable with the intuition Bonsanti describes.
Responsible for making such difficult decisions about our heritage, conservators long
for a scientific explanation. What do conservators do when there are no answers or
scientific basis for decision-making? Is it experience, intuition or moral rules that help
them make the decision as to what should be preserved?
How should conservators deal with objects like chemicals that are difficult or maybe
even impossible to conserve, which may be dangerous to the rest of the collection, or
whose aging process is unknown to them. Artefacts may, however, contain historical
information that may be an important part of our heritage. Can conservators decide to
dispose of the chemicals and save only their packaging? Can they destroy the
integrity of an object only because part of it may need special storage and
maintenance? Can museum visitors be deprived of seeing this “real thing” for which
they came to the museum?
And one more question: what kind of a conservator is best suited for the conservation
of chemicals? Conservation professionals are divided into specialized fields according
to the material of the museum object: paper, textile, wood, stone, ceramic, metal, etc.
Only art conservation has its own specialized fields that are not always connected to
the material of which an object is made.
In addition to the usual materials listed above, other strange and unusual materials
can be found in museum collections, particularly in natural history, ethnographic, or
medical museums. Chemical substances can also be found in other museums as a
part of their collection. For example in police museums where the majority of the
8
collection is uniforms and weapons, crime scene investigation related chemicals can
be found as well.
The conservation and preservation of such objects requires specialized knowledge.
For most of the chemicals in museum collections we can speak only about research
and preventive conservation. Active conservation is probably limited to cleaning and
conserving the chemical’s container. The eventual disposing of a part of the object
also belongs to the conservation of chemicals.
1.4. Chemical substances as an aspect of professional ethics
Many international bodies describe the code of ethics for the practice of conservation
of cultural materials. They underline some important aspects of conservation that
must be taken into consideration.
1 Conservation practice must be governed by an informed respect for cultural
property, and its unique character.
2 In the conservation of cultural material, all actions must be governed by an
unswerving respect for the physical, historic, aesthetic and cultural integrity of the
object. (AICCM 1999, p. 15).
The conservation professional’s respect for the integrity of the cultural property is
heavily stressed in these codes. When conserving a cultural property, the
conservator should respect the integrity of the object by endeavouring to preserve its
material composition and culturally significant qualities through minimal intervention.
The original intention, usage, history and evidence of the cultural property must be
respected. This respect for the integrity of the cultural property shall be based upon
the study of the cultural property. (CAC 2000, p.5).
According to the ICOM code of ethics, an intervention on an historic or artistic object
must follow the sequence common to all scientific methodology: investigation of
source, analysis, interpretation and synthesis. Only then can the completed treatment
9
preserve the physical integrity of the object, and make its significance accessible.
(ICOM 1984).
The changing role of museums initiated substantial changes in conservators’ work.
Conservators working for museums often consider conservation objects as their
clients, causing new museum directives to occasionally challenge the conservator’s
code of ethics. The changing role of the museums presented conservators with a new
way of looking at the objects and asking themselves: what is actually being preserved
when only the physical object is being conserved? The object should not be
perceived only as a physical being but as a whole concept. Also for this reason the
integrity of the object is very important. (Clavir 1996, pp.99 -107 )
Chemical substances belong to our heritage and are part of our cultural property.
Therefore they should be preserved and conserved according to a professional code
of ethics. Conservators play an important role in supporting the value of authenticity
and objects as historical evidence and this role also extends to difficult objects like
chemical substances. Chemical substances in a museum collection may cause many
problems, but by preserving the integrity of the object we guarantee that important
information is not destroyed.
Scientific methodology in the field of conservation has been used for many years
already. Scientific reasoning influences conservation and other work at museums.
The code of professional ethics may, however, conflict with science. There is a
special relationship between ethical beliefs and a scientific approach. A scientific
assertion can be tested using methodology, whereas ethical beliefs cannot be tested.
They are concerned with understanding how people view the nature of “reality” and
the underlying principles of value statements. (Clavir, 2002)
This divergence between professional ethics and pragmatic consideration can be
observed when approaching the problem of preserving chemical substances. Some
of them may be hazardous to health or pose a danger to the rest of the collection and
their possible preservation may be very costly and complicated. Their disposal seems
to be the easier way of solving the problem. The conservation code of ethics,
10
however, proposes that removing a part of an object, for example chemicals from
their container and disposing of them, is not ethical and does not respect the object’s
integrity. What values are more important? When deciding about preserving
hazardous substances many aspects must be weighed: on the one hand possible
dangers to people, on the other historical and cultural value. If the chemical in
question is a common, well known substance that is produced in large amounts
nowadays like, for example, acetic acid, the decision about disposal is easier to
make. It is more difficult to make a decision about an ethnographic object that
contains poisonous chemicals like curare (Strychnos toxifera) that has been used as
a paralyzing poison by South American Indians.
Conservators are burdened with decision making in these difficult situations. The
traditional conservation view that is most accepted states: “The conservator’s duty is
to take all possible precautions to prevent or minimize damage to the collection and to
oppose any situation, whether active or passive, that may cause or encourage any
form of deterioration. The welfare of the objects takes precedence over all other
considerations” (Ward 1986, pp 99 - 107).
When we consider the preservation of hazardous materials, however, the safety of
people and their health is the primary concern. The preservation of chemical
substances comes as a second. Every decision must be made separately for each
individual object and all aspects of preservation should be considered before
disposing. This leads to the conclusion that every chemical substance in the museum
collection should be researched and documented. Only based on that knowledge is
correct decision-making possible.
2. What kinds of chemical substances are encountered as historical objects?
Every conservator must first ask what the material of the conservation object is,
before he or she can start practical or preventive conservation. Therefore, the
11
question "What?” is a very important and basic one. When the conservation object is
a chemical substance the answer to the question “What?” is more difficult. The
identification of chemicals usually requires some training in chemistry and laboratory
equipment. Some chemicals in museums are in labelled containers but it is always
better to confirm the data by examination. The labelled container may contain some
other substance than the one named on the label, or chemical reactions could occur
in the substances changing the original contents.
2.1. Classification of chemical substances
Chemical substances can be divided in different ways according to their physical or
chemical properties. Each classification helps us recognize unknown substances.
Below are some criteria and their descriptions that can help classify unknown
chemical substances.
2.1.1.
Organic and inorganic substances
Basic classification of chemical substances is grouping into organic or inorganic
chemicals.
Organic substances consist primarily of carbon and hydrogen, but may also contain a
number of other elements, including nitrogen, oxygen, halogens, phosphorus, silicon
and sulphur. Organic compounds exist in an extremely large variety. The
classification of organic substances is not possible without having a full description of
the relative arrangement of the atoms within a molecule of the compounds. Other
elements present in hydro – carbon atomic structure are so-called functional groups.
They have a decisive influence on the chemical and physical characteristics of the
compound. Those containing the same atomic formations have similar characteristics,
which may be: solubility in water, acidity / alkalinity, chemical reactivity, oxidation
resistance and others.
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Organic compounds may be aliphatic, where the carbon chain is open or cyclic with a
closed carbon chain. Under those two groups there are many sub-groups that further
classify organic compounds.
Organic compounds often exist as mixtures. Organic mixtures usually dissolve in
organic solvents and separate. There are several methods for separating mixtures of
organic substances like: distillation, crystallization and chromatography.
In contrast to organic compounds, inorganic compounds are oxides, acids, salts,
carbides and minerals. Carbon can also be found in inorganic compounds but only in
simple carbon compounds that do not contain carbon – carbon bonds.
Large groups of compounds in inorganic chemistry are so-called coordination
compounds. A coordination compound is the product of a Lewis acid-base reaction in
which neutral molecules or anions (ligands) bond to a central metal atom (or ion) by
coordinate covalent bonds.
Coordination compounds and complexes are distinct chemical species - their
properties and behaviour are different from the metal atom/ion and ligands from which
they are composed.
2.1.2.
Solids and liquids
Resistance to deformation and changes of volume characterizes the solid state of
chemical compounds. Solid state has the following properties:
-
The atoms or molecules of solid substances are packed closely together
-
The atoms or molecules of solid substances have a fixed position in space
relative to each other. This accounts for the solid's rigidity
-
If sufficient force is applied, either of these properties can be violated, causing
permanent deformation
13
In liquid state particles of chemical compounds can freely move within the volume of
the container they are confined in. They form a surface that may not be necessarily
the same as that of the container. The volume of the liquid state of a chemical
compound is related to its temperature and pressure. The liquid compound forms a
surface that works as an elastic membrane that is characterized by surface tension.
Surface tension allows the formation of drops and bubbles. The phenomenon of
capillarity is also a result of surface tension.
Liquids generally expand when heated and contract when cooled. Liquids evaporate
on the surface even below the boiling point. Liquids can be mixed forming another
regular liquid or an emulsion or solution.
2.1.3.
Acids, bases and neutral substances
Chemical substances can be characterized by their acidity or alkalinity. Those
properties of chemical substances are measured by pH. The Danish chemist S.P.
Sørensen introduced the concept of pH. The pH scale is a reverse logarithmic
representation of relative hydrogen proton (H+) concentration in aqueous solution.
Acids are considered an opposite to bases and can be neutralized by them. Only
weak bases, such as soda, should be used to neutralize any acid spills. Neutralizing
acid spills with strong bases may cause a violent exothermic reaction, and the base
itself may cause just as much damage as the original acid spill.
2.1.3.1
Acids
Chemical compounds that dissolve in water, with a pH of less than 7 are considered
acidic. According to a modern definition by Johannes Nicolaus Brønsted and Martin
Lowry an acid is a compound which donates a hydrogen ion to another compound
called base.
Acids have the following properties:
14
-
Sour taste
-
Strong acids react aggressively with metals. Acid–metal reactions produce a
salt and hydrogen
-
Acids react with metal carbonates to produce water, carbon dioxide and salt
-
Acids react with bases to produce a salt and water. This is a so-called
neutralization reaction
-
Acids react with metal oxides to produce water and salt
-
Acids are electrolytes
-
Acids turn moist blue litmus paper red and methyl orange red
-
Many concentrated acids are very dangerous. They can cause severe burns
2.1.3.2.
Bases
Chemical compounds that dissolve in water with a pH of more than 7 are alkaline.
The bases are substances that can accept protons. Bases have the following
properties:
-
Bases have a bitter taste
-
Bases deteriorate organic materials
-
Bases react with acids (often violently) producing water and salt
-
Water solutions of bases conduct electricity
-
Bases turn red litmus paper blue
-
Strong bases, like strong acids are dangerous. They can cause serious burns
on the skin
2.1.4.
Toxic, dangerous and non-hazardous substances
Another way to classify chemical substances is according their effect on a human
being and their environment. In this classification we can speak about toxic
substances that have poisonous properties, dangerous substances that can cause
damage or safe substances.
2.1.4.1.
Hazardous substances
15
Hazardous chemicals are chemicals that can harm people, property, or the
environment. A hazardous substance may be radioactive, flammable, explosive, toxic,
corrosive, bio hazardous, an oxidizer, an asphyxiant, a pathogen, or an allergen.
The transportation, use, storage and disposal of hazardous materials is strictly
regulated by law to reduce the risk of injury and disaster. This must be considered
when planning the storage and exhibition of hazardous materials in a museum
setting. People who handle hazardous substances should be trained in all procedures
and precautions required.
There are several EU directives and regulations concerning the use of hazardous
substances issued. The most important is REACH (Regulation (EC) No1907/2006).
All hazardous chemicals should be marked by specific symbols. Appendices 1 and 2
contain valid EU symbols for hazardous materials and other common hazards.
Safety data sheets about hazardous substances are available on the Internet. A large
database can be found on the United States National Library of Medicine Website TOXNET. (Hazardous Substances Data Bank 2006)
In Finland all chemicals have their own safe usage data sheet (käyttöturvallisuustiedote) that can be found on the following website: www.käyttöturvallisuustiedote.fi
2.1.4.2.
Toxic substances
One group of hazardous materials is toxic substances. Toxic substances have an
effect on humans or other living organisms. Toxic substances can cause illness, injury
or death to living organisms. The toxicity may be caused by a chemical reaction or
other activity on molecular scale when a sufficient quantity is absorbed by the
organism. Toxic substances can work rapidly or can cause long-term poisoning when
organisms are exposed to them. When dealing with toxic substances extreme care
should be taken and regulations regarding toxic substances should be followed.
16
When dealing with an unknown chemical substance, all precautions against toxic and
hazardous materials should be taken.
The toxicity of the substance is affected by the method of exposure (dermic, inhaled,
ingested), time of exposure, and number of exposures.
Figure 1. EU standard toxic symbol, as defined by
Directive 67/548/EEC.
Poisons are usually symbolized by a skull and crossbones symbol. Chemicals that
are non-lethal may be toxic as well, but they are not marked with the same symbol. In
contrast to outright poisonous substances they may be harmful, irritating,
environmentally hazardous, or corrosive.
Toxic substances are seldom used for their toxicity but rather for other chemical and
physical properties.
Three types of toxic substances can be identified:
-
chemical toxins
-
physical toxins
-
biological toxins
Chemicals in museum collections typically represent one of the first two categories.
Biological toxins like bacteria or viruses are not typically collected by museums.
Radioactive materials, under the second category, can be found in museums.
17
Chemical toxins may be inorganic like, for example heavy metals, mercury and
hydrofluoric acid, or organic toxins. Most medications are organic toxins, for example
methyl alcohol.
Mixtures of chemicals are more difficult to assess in terms of toxicity than pure
substances and have to be studied carefully. When an unknown mixture is handled,
caution is always indicated.
2.1.4.3.
Non-hazardous substances
Non-hazardous substances can be classified as chemicals that are not toxic or
harmful to human beings or the environment in any other way.
Otherwise harmless chemicals can cause damage to museum objects under some
unforeseen circumstances. For example talc, which is a mineral powder composed of
hydrated magnesium silicate, can cause many problems for a conservator when
spilled over an object that is difficult to clean.
2.2. Ageing process
Common sense and chemical intuition suggest that the higher the temperature, the
faster a given chemical reaction will proceed. Quantitatively, the relationship between
the rate of the reaction and its temperature is determined by the Arrhenius equation.
The Arrhenius equation shows the dependence of the rate constant k of chemical
reactions on the temperature T (in Kelvin) and activation energy Ea.
k = Ae – Ea/RT
where A is the coefficient and R is the gas constant.
Chemical substances, just like everything else, age. Three types of ageing can be
recognized: physical ageing, photochemical deterioration and thermal degradation.
18
Ageing reactions for simple chemical substances are probably easier to predict than
for mixtures of substances or objects built of mixed materials.
Conservators’ concern is how to slow the process of ageing and deterioration and
predict the changes in physical and sometimes also chemical properties of materials.
For this reason we should study and understand the process. The contribution of
science to conservation problems is often applied to the examination of the museum
object but rarely to the investigation of material deterioration and preservation of
objects. This is most probably because the ageing process is very difficult to simulate
in a laboratory. The Arrhenius equation can be applied to the kinetics of chemical
transformation; the complex properties of many museum artefacts that are registered
during accelerated ageing cannot be simply related to their chemical composition.
Therefore testing some materials for accelerated aging will not always be related to
the natural aging of the artefacts. Only under certain conditions is the Arrhenius
equation applicable. (Zou 1996, pp 243 – 267).
For example, studies of the accelerated ageing of photographic materials prove that
the Arrhenius equation can provide valuable information if the degradation process at
elevated temperature proceeds by the same mechanism as at the storage
temperature. (Adelstein 1997, pp. 193 - 206).
Figure 2. Modes of oxygen
uptake versus time (according
to Feller 1994, pp 91-99).
19
For chemicals in museum collections predicting the ageing process can seem less
complicated when the chemical in question is common. The Arrhenius equation
should give the information about the aging reaction. The situation may, however, be
more complicated when the substance contains impurities or if it is a mixture.
According to the Arrhenius equation, lower temperature slows chemical reactions and
hence slows ageing. However, low temperatures can also have a negative effect on
some chemicals causing some physical changes like crystallization (olive oil).
In Figure 2, Feller proposes four basic ways of deterioration of organic substances.
The ageing process is rarely linear and changes in the properties of substances
seldom proceed at a steady rate (Fig 2a) but usually occur in stages.
The ageing often speeds up (Fig. 2b) or slows down (Fig. 2c) over time. The last chart
(Fig. 2d) presents a situation where in the beginning ageing accelerates and then
decelerates. The type of deterioration process presented in Fig. 2d can be very
difficult to study. In this type of deterioration there is a time at which no observable
changes occur in chemical or physical properties. That time is called induction time.
Only after the induction time is over can deterioration be observed. Conservators
should be very wary of that type of ageing because after the induction time, changes
in substances can be very rapid.
Recognizing the degradation profile of substances helps us estimate the possible
changes and the speed of the ageing process. This knowledge is very useful in
planning preventive conservation and, if possible, should be studied in a laboratory
utilizing accelerated ageing. Laboratory studies of the ageing process should attempt
to answer the following questions: Why do the physical changes occur? Can they be
avoided? How to slow the ageing process? Before good prevention practices and
treatment methods can be developed, it is necessary to study the ageing and
degradation processes of chemicals in museum collections. Only then can effective
conservation techniques can be applied.
20
2.3. Changes in the physical properties of chemical substances
Chemical substances have properties that help us identify them. These properties are
physical or chemical.
Physical properties do not change the chemical nature of
matter.
The more properties we can identify for a substance, the better we know the nature of
that substance. These properties can then help us model the substance and thus
understand how this substance will behave under various conditions.
Any aspect of a chemical substance that can be measured or perceived without
changing its identity is called a physical property. Below are listed some of the
physical properties of chemical substances: absorption, colour, concentration,
conductivity, density, dimensions, freezing point, boiling point, melting point, smell,
spectrum, weight, opacity, viscosity, and volume.
2.3.1. Changes in the state of matter
Chemical substances can be observed in three basic states of matter: solids, liquids
or gases. Every state of matter has typical physical attributes that differentiate that
state from the others. For example, liquids and gases do not have dimensions or
shapes. They are distinguished from each other in the way that gases are always
soluble in each other while two liquid phases may be insoluble (for example: water
and oil).
Chemical substances can change their state of matter. Different factors can cause
that change. However, the transformation of the state of matter is always connected
with energy.
Common transformations of the states of matter are:
-
Melting – freezing (liquid – solid)
21
When the internal energy of a solid is increased, usually by heat, to a melting
point it will change its physical phase to liquid. The opposite reaction is called
freezing.
-
Evaporation – condensation (liquid – gas)
During evaporation molecules of liquid become gaseous. Evaporation occurs
without the liquid being heated to boiling point. Liquids evaporate because their
molecules are in motion in random directions and that kinetic energy is enough
for the molecules to “fly off” the liquid surface. Evaporation rates differ for
different liquids. Some liquids are more volatile, like ether and others seem not
to evaporate at all, like oils.
The evaporation of a substance is affected by the concentration of the
substance in the air, temperature, ventilation, and the area of the evaporation
surface.
-
Sublimation – deposition (solid – gas)
Most chemical substances possess three different states at different
temperatures and the transition from solid to gas state goes through liquid
state. In some cases the transition from solid to gas is so rapid that no liquid
state can be observed. This process is called sublimation and the opposite
process deposition.
Examples of chemicals that can sublimate are: zinc, cadmium, iodine,
naphthalene, and arsenic (at high temperatures).
In the diagram below (Figure 3), pressure is presented on the Y-axis, and
temperature on the X-axis. The triple point is the temperature where the three states
(solid, liquid, gas) co-exist.
If the pressure is above the triple point the substance behaves as follows. A
substance is a solid at low temperature and at a given pressure. When the
temperature rises it reaches a point at which turns into a liquid. This is called the
melting point. If the temperature of liquid rises further it eventually reaches a
22
temperature at which it turns into a gas. This is the boiling point. When the pressure is
below the triple point the following happens: The substance is a solid at lower
temperatures. When heated the substance changes directly into a gas. This process
is called sublimation and the temperature at which the change in the state of matter
occurs is called the sublimation point.
The melting, boiling and sublimation points of a substance depend on the pressure.
Figure 3.
Triple point of
three existing phases.
Changes in the polymorphic phases of chemicals in museum collections are mostly
caused by temperature changes. Temperature changes can cause non-crystalline
chemicals to transform into crystalline form. This phenomenon can be observed, for
example, in olive oil at low temperatures.
According to Ellen Pearlstein:
"Fats and waxes, which are semi-solid at room temperature, will continue to respond
to subtle temperature changes with phase transitions, reaching a new equilibrium at a
new temperature … a varied temperature history and the inclusion of impurities in a
sample would make predictions of polymorphic behaviour almost impossible”.
(Pearlstein,1986, pp 83-91).
23
Some metals can exist in different allotropes that can be affected by temperature, for
example, tin. Beta tin allotrope at room temperature is a white metal but when the
temperature decreases alpha tin allotrope in the form of grey powder, becomes more
stable. That phenomenon affected Napoleon’s invasion of Moscow in 1812 when
soldiers’ buttons disintegrated. (Carrlee 2003, pp 141 -116).
2.3.2. Hygroscopic properties and reactions with water
Water in the form of moisture is present in our environment and greatly affects all
artefacts in museum collections that are hygroscopic or have the ability to react with
molecules of water.
Some chemical substances, like most organic materials and minerals are
hygroscopic. This means that they have the ability to absorb and desorb molecules of
water from the surrounding environment. Absorption and desorption of moisture
depend on the temperature and humidity conditions of the surrounding air.
Hygroscopic substances include glycerine, ethanol, methanol, and honey. Absorbing
water can change the physical and chemical properties of chemical substances.
Some chemicals, especially salts, are very hygroscopic. They can absorb large
amounts of water from the atmosphere and form liquid solutions. They change their
state of matter. Such chemicals are called deliquescent. The following are examples
of deliquescent compounds: calcium chloride, magnesium chloride, zinc chloride, and
sodium hydroxide.
Because of their affinity for atmospheric moisture hygroscopic substances should be
stored in sealed containers.
When assessing the risk to hygroscopic chemicals in museum collections
environmental conditions of the storage or exhibition space should be described and
controlled.
24
Examples of hygroscopic materials that can cause problems to a conservator are
sugar and honey.
There are many museums that collect decorative objects
containing sugar. The British Museum has a collection of sugar artefacts made in
Mexico for the celebration of the Day of the Dead (2nd of November). These artefacts
were collected in 1986. Just one year afterwards some white areas were yellowed.
This discoloration was caused by the deterioration of sugar due to hydrolysis. V.
Daniels and G. Lohneis explained the mechanism of sugar hydrolysis and its
discoloration. (Daniels 1997, pp.17 – 26).
Hydrolysis of sugar, i.e. its reaction with water, can convert sucrose into a syrup of
fructose and glucose, producing so-called invert sugar which is brownish in colour.
2.3.3. Sedimentation and separation of chemical substances
Chemicals that are in the form of a solution or suspension can sediment and
separate. Sedimentation is a phenomenon of motion of the molecules in a chemical
substance that is caused by an external force like gravity. Sedimented chemicals that
were supposed to be in one physical phase can be in two phases (liquid and solid).
Sedimentation can be difficult to observe if the mixture ingredients are in the same
physical phase. Only further examination of chemical properties can confirm the
separation.
Sediments can be divided into three groups:
-
Mechanical
Chemicals in suspension can separate because of the gravitational force and
deposit at the bottom of the container.
-
Chemical
Chemical sediments are formed by chemical reactions.
-
Organic
Organic sediments are formed as a result of actions performed by biological
organisms.
25
2.4. Changes in chemical properties
Chemical properties define the chemical nature of the substance. Chemical properties
are characteristics under certain conditions (temperature, atmospheric pressure).
Chemical properties become apparent during chemical reactions and are observed as
a change in the chemical identity of the substance.
Examples of chemical properties are: heat of combustion, reactivity with water, PH,
electromotive force, toxicity, stability, reactivity to other chemicals, and flammability,
Chemical changes result in one or more substances of a different composition being
created from the original substances. The atoms in the compounds are rearranged to
make new and different compounds.
Below are typical reactions that may occur in chemical substances.
-
Synthesis
A + B AB
-
Analysis (decomposition)
AB A + B
-
Substitution (single displacement)
AB + C AC + B
-
Double displacement
AB + CD  AC + BD
-
Chemical equilibrium


Chemical reactions result in chemical changes. For chemical substances that are in
museum collections they are always undesirable.
2.4.1. Oxidation reaction
26
The term oxidation was originally derived from the observation that almost all
elements react with oxygen to form compounds called, oxides. Now the scope of the
term has been extended and includes any reaction in which electrons are transferred.
This type of reaction is called redox (reduction – oxidation).
Oxidation and reduction always occur simultaneously. The substance that gains
electrons is called the oxidizing agent and the substance that loses electrons the
reducing agent.
Common oxidants are: oxygen, halogens, potassium permanganate, potassium
dichromate, and nitric acid. Common reductants are: metals, hydrogen, hydrogen
sulphide, carbon, carbon monoxide, and sulphurous acid.
Aniline serves as an example of an oxidation process. The collection of the Police
Museum in Tampere contains bottles of aniline that were used for producing a
reagent for testing diesel oil. The method was used by the traffic police for testing
diesel cars. Some were using fuel oil for its lower cost. The procedure is illegal
because the tax for fuel oil is lower than for diesel.
Aniline is normally colourless but it slowly oxidizes in air, changing colour to redbrown. The aniline that is now in the Police Museum collection is about 40 years old
and very dark in colour. It can be expected that with time it will finally convert into a
resin. (Morrison R.T. 1992)
2.4.2. Changes in colour
Every chemical substance absorbs a characteristic set of wavelengths of light. This is
the so-called absorption spectrum and can be used to identify the chemical. When the
chemical substance is altered in a chemical reaction its absorption spectrum will
change and so the created product will tend to be of a different colour.
Colour change is not always caused by a chemical reaction, because a compound’s
absorption spectrum is not the only factor affecting its colour. As an example, zinc
27
oxide changes colour from white to yellow when heated. Colour changes are caused
by holes and other defects that are created in the zinc oxide lattice and not by a
chemical reaction.
The aniline in the Police Museum serves as a good example of colour change.
Colour changes can also be observed in another chemical from the same collection.
White or almost transparent silver nitrate gets darker with time. The present, about 40
years old silver nitrate is greyish in colour.
2.4.3. Changes in odour
Humans can perceive volatilized chemical compound with their sense of smell. That
sensation is called an odour or smell and may be pleasant or unpleasant.
Organic compounds produce most of the odours although some inorganic chemicals,
for example ammonia or hydrogen sulphide, have characteristic odours as well.
Objective measure by the human nose is not possible because of the differences in
sensitivity and because of the psychological aspect of smelling sensations.
For most people odour gives little information about chemical substances and the
information is unreliable. Well known odours like alcohol, ammonia or petrol can
provide some knowledge of what we have in the container.
The intensity of odours can be classified and documented. Below is a typical scale of
describing the intensity of odour.
Odour intensity
0 - no odour
1 - very weak (odour threshold)
2 - weak
3 - obvious
4 - strong
5 - very strong
28
6 - intolerable
2.4.4. Precipitation
Formation of precipitate in a solution may occur as a result of chemical reactions.
This happens when, during a chemical reaction a solution is supersaturated by the
compound formed. In most situations precipitate moves to the bottom of the container
due to gravity. Precipitation is often a sign of chemical changes in a solution.
2.4.5. Predicting chemical changes
Most chemicals in museum collections are mixtures. Reactions between the
ingredients of the mixture must be carefully studied todelay the deterioration process
and eliminate unexpected and dangerous reactions. To help predict the ageing
process of a mixture of chemicals it is useful to make a chemical interaction matrix
that considers potential consequences of chemical reactions between the
components.
Whether two chemicals react, or react violently, may depend on
temperature, concentrations, impurities, or a number of other factors that are not
always readily understood or explained. In addition, chemicals may interact not only
with one another but also with their environment, including container, air or water and
other materials.
(http://www.hss.doe.gov/healthsafety/wshp/chem_safety/).
Below is an example of a chemical interaction matrix where two ingredients of the
mixture, container material, and environment are taken into consideration. The matrix
is filled with data collected from specialized sources, enabling conclusions about the
interactions between the factors studied. This kind of matrix may be added to the
conservation documentation, providing further information when planning the
preservation and storage of the object.
Some data on the compatibilities of chemicals can be found in an online database of
hazardous materials, CAMEO chemicals, http://cameochemicals.noaa.gov/. Making
29
the interaction matrix can be very useful in predicting possible reactions and changes
in chemical substances and planning preventive conservation of chemicals and their
storage environment.
Table 1. Generic Chemical Interaction Matrix
Chemical 1
Chemical
Glass
Rubber
Air
Water
Temperature
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
2
Chemical 1
Chemical 2
X
Glass
Rubber
Air
Water
Temperature
X
2.5. Effects of mould growth on chemicals in museum collections
Moulds and fungi can be found everywhere. They can grow on almost any substance
when the environmental conditions are appropriate. The presence of moulds can be
determined visually or by microscopic examination. Musty, earthy smell can also be
an indicator of moulds. If they are not visible or cannot be smellt, the presence of
mould can be determined by a laboratory test, letting a sample grow under controlled
conditions.
A very useful tool for determining the danger of mould growth on organic materials is
the so-called “Preservation Calculator“. This is a computer programme that can
estimate days when mould will grow, give approximate aging rates and preservation
indices when given the storage temperature and humidity. It is a good tool when
planning storage conditions for organic materials. It can be especially useful when the
danger of mould growth is present.
30
Figure 4. Preservation Calculator
Preservation Calculator can be downloaded from:
http://www.imagepermanenceinstitute.org
Mould growth is very dangerous to objects in museums, because it can impair organic
materials. It is also very dangerous to museum staff because of potential adverse
health effects. Mould growth on chemicals can also be dangerous for a unique
reason. Mould can change chemicals, making them volatile and causing them to
become airborne.
Recent research suggests that Napoleon’s death was probably caused by fungus.
Napoleon’s hair contained a small amount of arsenic, which would suggest a slow
poisoning of the Emperor. It was concluded that Comte de Montholon murdered
Napoleon for personal reasons. A more probable explanation is the wallpaper from
Longwood House on St. Helena Island. The wallpaper contained Scheele's Green
pigment. This pigment was copper arsenide that becomes toxic in damp conditions
because fungus growing on the paper excretes the poison as arsine gas. The
pigment was widely used in the Victorian era and there are many examples of arsenic
poisoning caused by that pigment. (Ledingham 1994).
31
2.6. Researching physical and chemical properties
The more properties we can identify for a substance, the better we understand its
nature. These properties can then help us model the substance and thus understand
how it will behave under various conditions.
For monitoring the ageing process, changes of one or a few distinguishing properties
of a chemical substance will yield useful information about suspected reactions.
The National Institute of Standards and Technology is a very useful source of
physical and chemical data on specific compounds. That data can be compared with
the results of testing a chemical substance. (http://webbook.nist.gov/chemistry/).
Various wet or instrumental analyses can be used for the identification of unknown
substances or for recognizing changes that may occur during the ageing of chemical
substances. The vast amount of literature on instrumental chemical analyses can be
a first step in making decision about the method used to analyse an unknown
chemical substance.
Electromagnetic spectra obtained by instrumental analysis methods are compared for
identification with existing spectra of known substances. There are many sources of
spectra of known substances. One of them is available on the Internet: The infrared
and Raman spectra database provided by Infrared and the Raman Users Group.
(http://www.irug.org/).
In this chapter the most common instrumental analysis methods are presented,
underlining the methods used during the conservation of chemicals from the
collection of The Police Museum in Tampere.
Table 2 presents the most commonly used instrumental analysis methods and the
information that can be collected from them.
32
Table 2. Most commonly used instrumental analysis methods
Method
What is it useful for?
Wet chemistry
VIS spectroscopy
FTIR spectroscopy
NIR spectroscopy
Raman spectroscopy
X-ray fluorescence
X-ray
Absorption
Near
Structure (XANES)
Wet chemistry techniques that are performed
in the liquid phase. They can be used for
qualitative
and
quantitative
chemical
measurements, such as: pH measurement,
viscosity, conductivity. Wet methods can be
used for the identification of ions.
Used in the quantitative determination of
solutions of transition metal ions and highly
conjugated organic compounds
Qualitative and quantitative analysis of organic
substances.
Qualitative and quantitative analysis of organic
substances.
Identification of chemical bonds and molecules.
It can also identify the crystallographic
orientation of a sample and is useful in the
identification of inorganic substances and
minerals.
Used for elemental analysis and chemical
analysis, particularly in the investigation of
metals, glass, ceramics
Edge Used for elemental analysis and determination
of oxidation level
Laser methods
Analysis of organic and inorganic compounds
Gas chromatography
Analysis of substances containing many organic
compounds
Method for separating a mixture of chemical
compounds
Liquid chromatography
33
2.6.1. Sampling
Sampling a chemical substance that is a museum object must be carefully
considered. The first question is if the container of the substance has ever been
opened. Some chemicals in museum collections are still in their original sealed
containers.
In Saint-Mere-Eglise there is an Airborne Museum with many medicines and other
chemicals that were a part of the equipment of American parachutists dropped into
France in June 1944. Most of them are still in their unopened containers. Similar
collections can be found in many war memorial museums.
Photo 1. Ossuarive de
Douaumont at Verdun, France.
Medical equipment from the First
World War.
Photo. 2. Airborne Museum at
Saint-Mere-Eglise, France.
Some of chemicals that were in
American parachutists’
equipment.
34
When containers are sealed it is probably best to accept that they contain the
substance that is written on the label. It is, however, necessary to study the
substance’s chemical and physical behaviour to ensure correct storage and to plan
preventive conservation.
Photo 1 represents a medical case with seven small vials that contain: ether, cocaine,
sparteine, ergotinine, caffeine, and morphine. The vials are sealed and there is no
reason to open them for research. Emptying the vials could be considered because of
the sensitive. Two of them contain illegal drugs. The exhibit should be very well
secured.
Unsealed containers, especially if they are not labelled, should be analysed (Photo 3).
Photo 3. Memorial Museum at Caen, France. Some medical equipment from
a German field hospital.
Most analysis methods require a very small sample and some of the samples can be
recovered after analysis. Sampling unknown substances should be done cautiously
and all possible precautions should be taken when opening containers and taking
samples. This procedure is best done at a chemistry laboratory where protective
equipment is available.
35
2.6.2. FTIR spectroscopy
Figure 5. Electromagnetic spectrum.
Figure 5 presents a full electromagnetic spectrum with the range of all possible
electromagnetic radiation. The electromagnetic spectrum of a substance is the
characteristic distribution of electromagnetic radiation from that object.
IR spectroscopy, meaning spectroscopy in the infrared region (4000 – 500 cm-1) is
most useful for the analysis of organic compounds and some inorganic substances. It
can also be used when analysing substances in a mixture; however, the best
identification results are achieved when the mixture is first separated. FTIR
spectroscopy will not accurately identify mixture ingredients that are less than 10% of
the mixture.
Photon energies associated with the infrared region are not large enough to excite
electrons, but may induce vibration of covalently bonded atoms and groups.
All
organic compounds will absorb infrared radiation that corresponds in energy to these
vibrations, either by stretching, bending or rocking. Infrared spectrometers are
permitted to obtain absorption spectra of compounds that are a unique reflection of
their molecular structure. Detailed information about the infrared absorptions
observed for various bonded atoms and groups is usually presented in tabular form.
Appendix 4 provides a collection of such data for the most common functional groups.
36
FTIR has different modes (transmission and reflection) that can analyse spectra from
various types of samples. Today's FTIR spectrophotometers are computerized, which
makes them faster and more sensitive than the older instruments. There also exist
wide IR-spectra databases that are used for comparison.
FTIR spectrophotometers are most useful for identifying types of chemical bonds and
functional groups of substances. The wavelength of light absorbed is a characteristic
of the chemical bond and based on this the compound can be identified. For most
common materials, the spectrum of an unknown material can be identified by
reference to a library of known compounds. To identify less common materials, IR will
need to be combined with other techniques.
In addition to qualitative analysis, FTIR can provide a quantitative analysis of a
mixture, because the strength of the absorption is proportional to the concentration of
a chemical. (http://orgchem.colorado.edu/. 2008)
2.6.3. NIR - Near Infrared Spectroscopy
NIR spectroscopy is spectroscopy in the near infrared region, from 800 nm to 2500
nm. This method can be used for qualitative and quantitative analysis. Because
electromagnetic penetration for near infrared waves is deeper than for IR, analysis of
samples in a glass container can be performed without the need to open it.
2.6.4. X-Ray Fluorescence Spectroscopy
The X-ray fluorescence is an analytical technique based on the interaction between
X-rays and the substance under analysis to determinate its elemental composition.
XRF is suitable for solids, liquids and powders. It is applicable over a wide range of
concentrations, from 100% down to parts per million. XRF is very well suited for fast
qualitative elemental analysis. Normally it can identify elements from sodium to
uranium. It does not need any special sample preparation. The XRF method can also
37
be used for quantitative analysis because the peak height for any element is directly
related to the concentration of that element. (http://www.amptek.com/xrf.html. 2008)
XRF method is non-destructive and can be used in situ. When a radioactive photon
from an x-ray tube or a radioactive source strikes a sample, the X-ray can either be
absorbed by the atom or scattered through the material. When an X-ray is absorbed
by the atom it transfers all of its energy to the innermost electron.
During this
process, if the primary X-ray has sufficient energy, electrons are ejected from the
inner shells, creating vacancies. These vacancies present an unstable condition for
the atom. As the atom returns to its stable condition, electrons from the outer shells
are transferred to the inner shells and in the process gives off a characteristic x-ray
whose energy is the difference between the two binding energies of the
corresponding shells. Because each element has a unique set of energy levels, each
element produces x-rays at a unique set of energies, making it possible to nondestructively measure the elemental composition of a sample. (Knuutinen. 2006, pp 1
-85).
2.6.5. X-ray Absorption Near Edge Structure (XANES)
XANES is X-ray absorption spectroscopy used for the identification of substances. It
is most useful for determining the oxidation state of elements. It is also used to
determine the proportions of each compound in a sample.
2.6.6. Raman spectroscopy
Raman spectroscopy is widely used in chemistry for the identification of chemical
bonds and molecules. It gives characteristic spectra for organic molecules in the
range 500 –2000 cm-1. It can also identify the crystallographic orientation of a sample
and is useful in the identification of inorganic substances and minerals. Raman
spectroscopy is a non-destructive analytical method and the instrument used can be
portable. Raman spectra can be collected from a very small sample (< 1 µm in
38
diameter). Raman spectroscopy is suitable for the identification of minerals, polymers,
and proteins.
2.6.7. Laser methods
There are several laser methods that are used for the chemical analysis of inorganic
and organic compounds, like:
-
LIBS (Laser Induced Breakdown Spectroscopy). This technique offers
qualitative and quantitative elemental analysis with a spectral range of 200 980 nm. The method can be used for the identification of inorganic substances.
-
LIF (Laser Induced Fluorescence). This method can be used for analyzing
inorganic and organic substances.
-
LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectrometry) is
a very sensitive analytical method for rapid multi-element determination in the
trace range of inorganic solid sample materials. (Kolar, Strlič, 2007)
2.6.8. Chromatography methods
Chromatography is a separation method that uses differences in partitioning
behaviour between a flowing mobile phase and a stationary phase to separate the
components in a mixture. After separation sample components are analysed.
-
Gas chromatography is used for volatile organic compounds.
-
High-performance liquid chromatography separates analytes based on polarity
-
Liquid chromatography is used for separating ions and molecules that are
dissolved in a solvent.
-
Size-exclusion chromatography is a separation method in which particles are
separated according to their size. SEC is used for the analysis of synthetic and
biological polymers.
-
Thin-layer chromatography, a simple and rapid method for separation of
organic compounds.
39
2.7. Molecular Diversity Preservation International
Molecular Diversity Preservation International (MDPI) is an organisation for the
deposit
and
exchange
of
molecular
and
bio-molecular
samples.
(http://www.mdpi.org/).
The MDPI is a non-profit organization in Switzerland. Its mission is to preserve
historically significant chemical samples in the Chemical Museum in Basel.
The organisation also participates in sharing and exchanging rare chemical samples
for research purposes.
If a museum has some rare chemicals but is unable or unwilling to store them, it can
deposit them at the MDPI. Samples should be stable at room temperature, pure and
non-hazardous. The quantities of deposits are from 10 mg to 100 g. Samples of
chemicals can be also borrowed for chemical, non-destructive use.
2.8. Documentation of chemical substances in a museum
Documentation of artefacts is very important for conservation. Using knowledge
gathered in documentation and during the historical and physical research of the
artefact, conservators can better make their decisions concerning the object. The
documentation of the artefacts is also a very important tool for communication both in
the present and in the future. Documentation has three important roles: it can be used
instead of the real object for historical research, it contains the known history of the
artefact and it helps safeguard the artefacts because it contains storage instructions.
All information gathered in the artefact’s documentation should be reliable and their
sources cited. (Häkäri. 2001).
In the documentation of chemical substances in museum collections conservators
should include in addition to aspects that are usually included in artefact
documentation, chemical analysis, safety instructions and information for the safe
40
handling and storage of chemicals. For drugs whose possession is regulated by law,
the required document should also be attached as well.
The documentation of chemical substances should include:
1. description of chemicals: container and chemical
2. origin of the chemical substance
3. ownership and history of ownership
4. identification, knowledge and description of what it was used for and by whom
5. condition
6. possible conservation report
7. safety instructions for handling and storage and possible dangers that can be
caused by the chemical
8. photographs of the artifact
3. Chemicals in the Police Museum collection in Tampere, Finland
As empirical research of a chemicals collection, I studied the collection of the Police
Museum in Tampere.
In 1995, the Ministry for Internal Affairs in Finland started a project that surveyed
historical police material from all municipalities in Finland. The museum material was
inventoried and in 2003 the decision about the establishment of a national Police
Museum was taken. The Police Museum was established in 2004.
Chemicals that were found in the collection of the Police Museum in Tampere were
donated by the Police Technical Centre from Helsinki and by the Traffic Police
Department.
3.1. Where do they come from?
Most of the museum collection comprises artefacts from the Police Technical Centre
and artefacts that concern the Traffic Police Department.
41
In the group of objects that belonged to the traffic police are two interesting field
laboratory bags from the 1960s. The chemicals from those bags were used for testing
diesel oil. In Finland the tax on fuel oil was lower than on diesel oil, and therefore
some people used it instead diesel oil or mixed the two. The fuel oil was not coloured
as it is nowadays and was difficult to recognize without chemical testing. The field
laboratory bags contain chemicals that were used for identifying fuel oil. Two
reagents, aniline and acetic acid, were used. The reagents were mixed and added to
the tested oil. If the sample contained fuel oil instead of diesel, a dark red circle was
formed between the oil and the reagent. If the sample contained a mixture of fuel and
diesel oil the red circle was not so clear. Pure diesel oil gave no reaction. If there was
a reaction and the traffic police suspected the use of illegal fuel oil in the vehicle or
other engine, the sample was sent to the Laboratory of the Customs Department for
further investigation. The Laboratory of Customs Department belongs to the Tax
Office which controls the taxation of fuel.
Lappalainen in his interview explained about preparing the reagent for testing fuel oil.
He raported that the required chemical reagents, aniline and acetic acid, were bought
from a pharmacy and mixed before testing at the police station. He remembered that
prepared reagents were useful for only a few days. When old, white crystals were
formed on the bottom of the reagent container and the expected reactions did not
occur. The containers with dark liquid and white crystals were found in the field
laboratory bags deposited at the Police Museum likewise test tubes with tested
samples. (Lappalainen 2007).
Below is a text translated from Finnish, found in one of the field laboratory bags
explaining the preparation of the reagent and testing the sample of suspected oil.
The second group of chemicals found in the Police Museum in Tampere are
chemicals from the Police Technical Centre. These chemicals were used for crime
investigation and photographic purposes. The purpose of some of the chemicals is
very difficult to guess.
42
Information about some of the chemicals was provided by Ilkka Sjöman of the Police
School in Tampere.
That group of chemicals included:
-
Iodine used for developing fingerprints on paper
-
Chemicals like Malachite Green, Fuchsine used for colouring samples
investigated under a microscope. According to Sjörman, Fuchsine was
sometimes used as a “trapping colour” for objects that might be stolen.
-
Silver Nitrate used in photography
There are also solvents used in a laboratory like acetone, aseptic liquid – Neoamisept, but also chemicals whose use is unknown like “siansappi viinan “ that
can be translated into English as “pig’s bile in ethanol”.
3.2. Present condition and storage of chemicals at the Police Museum in Tampere
Before the conservation evaluation and treatment chemicals received from Helsinki
Police Technical Centre and Traffic Police Department were stored in a temporary
storage place together with other artefacts. They did not have their own separate
storage space and no safe storage containers. Chemicals were stored in their original
containers and bottles. Some of the containers or their lids were damaged (Photo 4
and Photo 5). Placement of the containers was not planned and some dangerous
chemicals like a strong oxidizer - silver nitrate could be placed close to flammable
acetone.
Most of the chemicals were in small containers that were packed in open cardboard
boxes. The cardboard boxes did not give sufficient protection if some of the chemical
containers were broken.
Chemicals used in field testing by traffic police were stored in their original containers
placed in bags, the same way as during their lifetime (Photo 6). Some of the
chemicals used for testing diesel oil were dangerous. In one of the field laboratory
bags, two testing tubes with unknown liquids were found (Photo 7). The field
43
laboratory bags were made of cardboard and their inner surfaces were covered with
paper in one case and with PVC film in another. Both surface materials could be
easily irreparably damaged if aniline or acetic acid made to affect them.
Photo 4. Damaged container
with silver nitrate from the
collection
Museum.
of
the
Police
Photo 5. Bottle of aniline
with damaged lid, from
the
collection
Police Museum.
of
the
44
Photo 6. Field equipment bag of chemicals for testing the purity of gasoline. From the
collection of the Police Museum.
Photo 7. Test tubes with unknown
liquid found in one of the mobile police
field bags for testing the purity of
gasoline. Police Museum collection.
45
3.3. Types of chemicals in the collection of the Police Museum in Tampere and their
characteristic.
There are thirty-four chemicals in the collection of the Police Museum in Tampere that
can be grouped and characterized in different ways. Some bottles contain the same
chemicals.
There are eight solid chemicals and twenty two liquids. There are also samples that
are liquid but contain crystals.
Table 3. Labelled chemicals from Police Museum collection.
Nr
Name of chemical, taken from label
State
1
Anthracene Technical
solid
2
Zinc Silicate
solid
3
Argent. Nitr.Ph.F.VI (hopeanitraatti)
solid
4
1-Naphthylamine-4-sulphonic acid
solid
5
Peroxide, 3%
liquid
6
Paraffin
liquid
7
Glycerin
liquid
8
Acetone
liquid
9
Neo-amisept
liquid
10
Malachite green
solid
11
Fuchsine
solid
12
Tetrabromphenolsulfophtalein
solid
13
Clove oil
liquid
14
Iodine
solid
15
Iodine + sol.calc.chloride cntr
liquid
16
Unknown,
labelled
in
Finnish
: liquid
Siansappi viinan
17
Acetic acid
liquid
18
Aniline
liquid
46
Table 3 presents the full list of chemicals that are in their original containers with
labels.
There are also seven containers containing unknown liquid substances. All the
unknown chemicals were found in the field laboratory bags for testing fuel oil.
3.4. Identification of chemicals from the collection of the Police Museum in Tampere
The conservation process and decision-making concerning chemicals from the Police
Museum in Tampere was preceded by researching of the objects that could help
identify unknown substances and confirm labelled ones.
In analysing chemicals the methods available to EVTEK Design Institute,
Conservation Laboratory were used. The main research tool was the FTIR
spectrophotometer that helped to analyse most of the organic substances. The acidity
of unknown chemicals was measured by pH-meter and elemental contents of solid
chemicals defined by XRF.
Other physical parameters were described using
organoleptic methods.
3.4.1. Description of conservation objects
In the description of conservation objects, both containers and chemicals were
described. Table 4 lists chemicals obtained from the Police Technical Department of
Helsinki. Table 5 and Table 6 present chemicals from field laboratory bags obtained
from the Police Traffic Department. Most of the chemicals in Tables 5 and 6 are
unknown.
Table 4. Chemicals from the Police Technical Department of Helsinki.
Nr
1.
Label
Description
BDH Anthracene Technical The British Chemical:
Drug
Houses
Ltd.
London Gray powder
47
20082191:4701 250 Grams
2.
3.
4.
5.
BDH Zinc Silicate made in England
The British Drug Houses Ltd. B.D.H.
Laboratory Chemicals Group Poole
England
..mpereen Rohdos Oy Helsinki 250,0
Argent. nitr. Ph. F. VI. …mmerfors
Drog
Ab
Helsingfors”
and
”Hopeanitraatti” which means silver
nitrate
“BDH
laboratory
reagent,
1Naphtylamine-4sulphonic
Acid
NH2C10H6
SO3Na4H2O=317,32
(Naphthionic acid) Purified sodium
salt, made in England, The British
Drug Houses Ltd. B.D.H. Laboratory
Chemicals Group Poole England
668308/520222 100 g net” and second
one “ Tuonti-import Rohdoskeskus Oy
Drogcentral Ab Helsinki-Helsingfors
Puh. 65806 Tel”
“Vätesuperoxidlösning
3%
Till
sårbehandling outspädd, till gurgling
utspädd med 3-5 deler vatten Apoteket
Hjorten Västerås”
Quantity: about 100 ml
Container:
Dark brown glass container
black plastic screw top.
Dimensions:
height: 15 cm, diameter: 7 cm
Chemical:
White-grayish powder
Quantity: about 50 ml
Container:
Dark brown glass container
black plastic screw top.
Dimensions:
height: 12 cm, diameter: 6,5 cm
Chemical:
Hardened grayish powder.
Quantity: about 100 ml
Container:
Dark brown glass container
black plastic screw top.
Dimensions:
height: 9,5 cm, diameter: 6 cm
Chemical:
White powder
Quantity: 20 ml
Container:
Dark brown glass container
black plastic screw top.
Dimensions:
height: 11 cm, diameter: 5,5 cm
with
with
with
with
Chemical:
Transparent liquid.
Quantity: about 100 ml
Container:
Dark brown glass bottle with black
plastic screw top.
Dimensions:
height: 18 cm, diameter: 6,5 cm
48
6.
„Gdanski Zarzad Aptek Laboratorium
Goleniowe Ilosc 200 g, Cena z opak.
6,90, Parafina oczyszczona F.P.III,
wewnetrzne Nr serii 440459”
7.
“Runeberg Runeberink.25 Puhelin
42640 Glyseriiniä Glyserin A/b Erna
O/y”
8.
a. Three labels: ”Kruunuhaan uusi
apteekki Snellmanink. 13 Puh.
665500,
625500,
Asetonia
Aceton”,
”Ulkonaisesti Utvärtes”
”tulenarkaa eldfarligt LKKL”
b. Two
labels:
”Willhelmsin
apteekki,
Asetonia
Aceton
Ulkonaisesti Utvärtes Willhelms
Apotek” and
”tulenarkaa
eldfarligt”
9.
”Neo-Amisept
desinfioimisaine
–
desinfektionsmedel Sisältää 0,2%
suurimolekyylistä
dialkyylimetyyliammoniumkloridia
–
Käytetään laimentamattomana ihon
Chemical:
Thick transparent liquid. In liquid
fragments of natural cork and
unknown plastic (?) film can be
found.
Quantity: about 50 ml
Container:
Bluish glass bottle with grey rubber
top.
Dimensions:
height: 19 cm, diameter: 6 cm
Chemical:
Thick transparent liquid.
Quantity: about 20 ml
Container:
Bluish glass bottle with red plastic
screw top.
Dimensions: 14,5 cm x 6 cm x 2 cm
a. Chemical:
Transparent liquid
Quantity: about 4 ml
Container:
Dark brown glass bottle with
black plastic screw top.
Dimensions:
height: 10 cm, diameter: 3,5
cm
b. Chemical:
Transparent liquid
Quantity: about 10 ml.
Container:
Dark brown glass bottle with
black plastic screw top.
Dimensions:
height: 10 cm, diameter: 3,5
cm
Chemical:
Transparent liquid
Quantity: about 100 ml.
Container:
Glass bottle with white plastic screw
49
10.
11.
12.
desinfiointiin ennen lääkintätehtäviä,
puoleksi vedellä laimenettuna ihon
pyyhkeisiin ja haudekääreisiin. NeoAmiseptilla on hyvä rasvanliuotuskyky
ja liuotin haihtuu iholta nopeasti. Se
soveltuukin erinomaisesti käytettäväksi
spriin tai eetterin asemasta ja on näitä
tehokkaampi. Ei sekoiteta saippuaan.
Vaarallista nautittavaksi. Tulenarkaa
1lk., 200 ml, Lääke Oy”
Two labels: “1397 100 g Malachitgrün,
konzentriert, Malachite-Green, Made
in
Germany,
Verde
Malaquita
concentr, Fabricacion Alemana, Verte
Malachite concentre, Verde Malachite
concentr. Verde Malachita concentr.
53054, E. Merck Darmstadt” and
“Malakiittivihreä”
a. ”10 gr Fuchsin 22015
Mikroscop. Farbstoff Ciba”
S
b. ”10 gr Fuchsin 22015
Mikroscop. Farbstoff Ciba”
S
”Yliopiston Apteekki
tetrabromphenolsulfophtalein. 5,0”
top.
Dimensions:
height: 16 cm, diameter: 5 cm
Chemical:
Gray, small crystals.
Quantity: about 10 ml
Container:
Dark brown glass container with dark
red plastic screw top.
Dimensions:
height: 12 cm, diameter: 5,5 cm
a. Chemical:
Dark red-greyish powder.
Quantity: about 5 ml.
Container:
Dark brown glass bottle with
dark brown plastic screw top.
Dimensions:
height: 8 cm, diameter: 3 cm
b. Chemical:
Dark red-greyish powder.
Quantity: about 5 ml.
Container:
Dark brown glass bottle with
dark brown plastic screw top.
Dimensions:
height: 8 cm, diameter: 3 cm
Chemical:
White powder
Quantity: about 10 ml
50
13.
Container:
Dark brown glass bottle with black
plastic screw top. On the top text:”E.
Merck. Darmstadt”.
Dimensions:
height: 5 cm, diameter: 2,5 cm
”Korppi Apteekki, Helsinki Neilikkaöljyä Chemical:
Nejlikolja
Apoteket
Korpen, Dark brown thick, fragrant liquid.
Helsingfors”
Quantity: about 20 ml
Container:
Dark brown glass bottle with black
plastic screw top.
Dimensions:
height: 5,5 cm, diameter: 3 cm
14.
a. Two labels: ”Tampereen Rohdos Oy
Tammerfors Drog AB Helsinki –
Helsingfors, 500,0 jodum, Anal. No
60081 Ph. Nord..” and ”Korppi
apteekki Helsinki Etelä-Esplanaadi 2
Puh 628183, Jodikiteitä, Apoteket
Korpen,
Helsingfors,
Södra
Esplanaden 2 Tel. 628 183”.
a. Chemical:
Grey hard crystals.
Quantity: about 100 ml
Container:
Dark brown glass bottle with black
plastic screw top. On the top text:”E.
Merck. Darmstad”.
Dimensions:
height: 14 cm, diameter: 6 cm
b. Two labels: ”Korppi Apteekki
b. Chemical:
Helsinki 13 Eteläinen Esplanaadikatu Hard grey crystals.
2 Puh. 628 183 Jodikiteitä Apoteket Quantity: about 100 ml
korpen
Helsingfors
13,
Södra
Esplanadgatan 2 Tel 628 183” and
Container:
”ulkoisesti
nauttiminen
vaarallista Dark brown glass bottle with glass
utvärtes farligt att förtära”.
top.
Dimensions:
height: 19 cm, diameter: 8 cm
c. ”Jodikiteitä”
c. Chemical:
Hard grey crystals.
Quantity: about 100 ml
Container:
51
15.
16.
Glass bottle with glass top.
Dimensions:
height: 17,5 cm, diameter: 8 cm
”Kauppatorin Apteekki Apoteket Vid Chemical:
salutorget Helsingissä Helsingfors Dark brown liquid.
17/II-40 Jodicalcium liuos. (1,0 Jod.- Quantity: about 50 ml
2,0 Jod. kal.-97 ccm.) =1,0 Sol.calc.
chloride.cntr.-4,0 175.0 M.ds)”
Container:
Dark brown glass bottle with natural
cork top.
Dimensions: 16 cm x 6 cm x 3 cm
”Erottajan Apteekki Apoteket vid Chemical:
Skillnaden Helsinki, H:fors, Siansappi Brown thick liquid. In the bottle are
viinan2
fragments of broken natural cork.
Quantity: about 5 ml
Container:
Glass bottle with natural cork top.
Dimensions: 11 cm x 4,5 cm x 2 cm
Table 5. Chemicals from field laboratory bag A.
Nr.
1
2
Name
Unknown
Description
Chemical:
Dark brown liquid.
Quantity: about 20 ml
Container:
Glass bottle with white metal screw
top. On the bottle is a paper label with
text”Vaasan
Keskusapteekki
puh.
2101, 4099, Tisl. vettä Dest. vatten Ph.
F. VI, Centralapoteket i Vasa tel 2101,
4099”.
The bottle is an old Alko bottle with
remnants of the old product label.
Dimensions:
height: 23,5 cm, diameter: 7 cm
Unknown, on the label written name Chemical:
“reagenssi”
Dark brown liquid. On the bottom of
the bottle there are white crystals.
Quantity: about 50 ml
52
3
4
5
Container:
Glass bottle with grey rubber top. On
the bottle is a blue plastic label with
text:
”REAGENSSI”.
Dimensions:
height: 18 cm, diameter: 8 cm
Unknown
Chemical:
Dark brown liquid. On the bottom of
the bottle are white crystals. Strong
smell of gasoline.
Quantity: about 50 ml
Container:
Brown glass bottle with glass top.
Dimensions:
height: 16,5 cm, diameter: 6 cm
Unknown
Chemical:
Dark brown liquid. Strong smell of
gasoline.
Quantity: about 500 ml
Container:
Glass bottle with white metal screw
top.
The bottle is an old “Alko” bottle with
remnants of the old product label still
exist. The text on the old product-label
is: ”Product of Finland Dry Vodka
unflavoured 45° Produced and bottled
by Oy Alko Ab Helsinki Finland 015
Distilled from grain”
Dimensions:
height: 23 cm, diameter: 6,5 cm
Unknown on the label written name Chemical:
“jääetikka”
Dark brown liquid.
Quantity: about 200 ml
Container:
Glass bottle with black rubber top. On
the bottle is a blue plastic label with
text ”JÄÄETIKKA”.
Dimensions:
height: 18,5 cm, diameter: 8 cm
53
Table 6. Chemicals from field laboratory bag B.
Nr.
1.
Name
Acetic Acid, “Etikkahappo”
2.
Unknown
3.
“Aniline”
4.
“Aniline”
Description
Chemical:
Transparent liquid with strong acetic
smell.
Quantity: about 500 ml
Container:
Brown glass bottle with black plastic
screw top. On the bottle is a paper
label with text: ”Etikkahappo väk. yli
90%…” .
Dimensions:
height: 19,5 cm, diameter: 7 cm
Chemical:
Dark brown liquid with acetic smell.
The liquid contain long, white crystals.
Quantity: about 200 ml
Container:
Glass bottle with grey rubber top. On
the bottle is a paper label with text:
”Valmis sekoitus 20.07.87”.
Dimensions:
height: 19 cm, diameter: 8 cm
Chemical:
Dark brown liquid.
Quantity: about 20 ml
Container:
Brown glass bottle with white plastic
screw top. On the bottle are two paper
labels with text: ”pro analysi art 1261
Anilin zur analyse C6H5NH2 MERCK
…” and “Myrkkyä …. GIFT Livsfarligt
att förtära”.
Dimensions:
height: 15 cm, diameter: 6,5 cm
Chemical:
Dark brown liquid.
54
5.
Acetic Acid, “Etikkahappo 1987”
6.
Unknown
7.
“Aniline”
8.
“Aniline”
Quantity: about 400 ml
Container:
Brown glass bottle with white plastic
screw top. On the bottle is a paper
label with text:”pro analysi art 1261
Anilin zur analyse C6H5NH2 MERCK
…”
Dimensions:
height: 15 cm, diameter: 6,5 cm
Chemical:
Transparent liquid with strong acetic
smell.
Quantity: about 500 ml
Container:
Brown glass bottle with black plastic
screw top. On the bottle are two paper
labels with text: ”Etikkahappo väk. yli
90%…” and ”Hankittu 17.7.87”.
Dimensions:
height: 19,5 cm, diameter: 7 cm
Chemical:
Dark brown liquid with acetic smell
Quantity: about 200 ml
Container:
Glass bottle with black rubber top. On
the bottle is a paper label with text:
”JÄÄETIKKAA”
Dimensions:
height: 18 cm, diameter: 8 cm
Chemical:
Dark brown liquid.
Quantity: about 400 ml
Container:
Brown glass bottle with white plastic
screw top. On the bottle is a paper
label with text:”pro analysi art 1261
Anilin zur analyse C6H5NH2 MERCK
…”
Dimensions:
height: 15 cm, diameter: 6,5 cm
Chemical:
55
Dark brown liquid.
Quantity: about 400 ml
Container:
Brown glass bottle with white plastic
screw top. On the bottle is a paper
label with text: ”pro analysi art 1261
Anilin zur analyse C6H5NH2 MERCK
…”
Dimensions:
height: 15 cm, diameter: 6,5 cm
In the field laboratory bag there were also six test tubes. Two of them contained about
20 ml of dark liquid that smellet like fuel oil or diesel. The laboratory tubes were
closed with grey rubber stoppers. The content of both tubes were analysed by FTIRspectrophotometer.
3.4.2. FTIR spectroscopy
The interpretation of infrared spectra involves the correlation of absorption bands in
the spectrum of an unknown compound with the known absorption frequencies for
types of bonds. Intensity, shape, and position in the spectrum are significant for the
identification of the source of an absorption band. The method of running the
spectrum can affect the results and sometimes comparisons can be very difficult.
Very small samples of all chemicals from the collection of the Police Museum were
run by FTIR-spectrophotometer Perkin Elmer Spectrum 100 using ATR micro-analyse
method.
Attenuated total reflection infrared (ATR-IR) spectroscopy is used for analysis of the
surface of materials. For most materials, no sample preparation is required for ATR
analysis.
For attenuated total reflection infrared spectroscopy, infrared radiation is passed
through an infrared transmitting crystal with a high refractive index, allowing the
radiation to reflect within the ATR element several times.
56
IR-spectra received were compared to existing IR spectra in IR libraries available on
the
Internet
and
in
the
literature.
(http://www.irug.org,
2007
and
www.webbook.nist.gov/chemistry, 2007). In the interpretation of IR-spectra Table of
Characteristic IR Absorptions was used as well. (http://orgchem.colorado.edu/). The
Table is presented in Appendix4.
IR spectra of chemicals from the Police Museum and their comparison to the known
spectra are presented in Appendix 3.
Comparisons of the chemicals received by the Police Museum from the Technical
Department of Helsinki Police are presented in Appendix 3. IR spectra from IR
spectra libraries are presented on a different scale than the spectra run from the
museum’s collection in the EVTEK Design Institute Laboratory and their comparison
can be difficult. Identification was done by comparing places of characteristic peaks
and their shape.
Below are the IR spectra of the unknown substances from the field laboratory bags
and their analysis. The IR spectrum of the mysterious substance named “siansappi
viinan” is also presented.
Field laboratory bag 1
1. Unknown sample 1
57
Figure 6. IR spectrum of unknown sample 1 from laboratory bag 1.
Figure 7. IR spectrum of acetic acid.
58
Figure 8. IR spectrum of aniline.
The brown colour of the sample suggests that it may contain aniline. The very low pH
(pH measurement results are presented in Table 5 in Chapter 2.4.9.2) and peaks
characteristic for the carbonyl group suggests that most probably the sample is a
mixture of acetic acid and aniline. Mixture is a readymade reagent for testing diesel oil
for the presence of fuel oil.
2. Unknown sample 2
59
Figure 9. IR spectrum of unknown sample 2 from laboratory bag 1.
The dark brown liquid with very low pH and similar IR spectrum to that of sample 1
suggests that the chemical in question is a mixture of acetic acid and aniline. It is a
readymade reagent for testing diesel oil.
3. Unknown sample 3
60
Figure 10. IR spectrum of unknown sample 3, from laboratory bag 1.
Figure 11. IR spectrum of petroleum according to http://search.be.acros.com/
(accessed 2.1.2008).
61
The unknown brown liquid with a strong smell of gasoline is probably a petroleum
sample taken from a tested car. The presence of a small peak characteristic for the
carbonyl group and low pH suggests that the sample is contaminated with acetic acid
or readymade testing reagent.
4. Unknown sample 4
Figure 12. IR spectrum of unknown sample 4, from laboratory bag 1.
The simple IR spectrum is characteristic of the alkenes group, the almost neutral pH
and strong gasoline smell of dark brown liquid sample suggest that it is a sample of
Diesel oil taken from the suspected car.
62
Unknown sample 5
Figure 13. IR spectrum of unknown sample 5, from laboratory bag 1.
Figure 14. IR spectrum of acetic acid from http://search.be.acros.com/, (accessed
2.1.2008).
63
The unknown chemical number 5 from the field laboratory bag contains acetic acid.
The dark brown colour probably comes from slight contamination by aniline. The
aniline content is probably so small that the characteristic peaks are covered by the
acetic acid spectra.
Field laboratory bag 2
1. Unknown sample 1
Figure 15. IR spectrum of unknown sample 1, from laboratory bag 2.
Based on the IR spectrum, pH and strong acetic acid smell we can confirm that the
bottle contains acetic acid.
64
2. Unknown sample 2
Figure 16. IR spectrum of unknown sample 2, from laboratory bag 2.
The dark brown liquid with very low pH and similar IR spectrum as that of samples 1
and 2 from laboratory bag 1 suggests that the chemical in question is a mixture of
acetic acid and aniline. It is a readymade reagent for testing diesel oil. The white
crystals in the sample are a result of a reaction taking place between these two
chemicals. According to p.c. Lappalainen, the reagent could be used for only a short
time (about one week) and after that it no longer worked and white crystals
sedimented in the container. (Lappalainen 2007).
65
3. Unknown sample 3
Figure 17. IR spectrum of unknown sample 3, from laboratory bag 2.
4. Unknown sample 4
Figure 18. IR spectrum of unknown sample 4, from laboratory bag 2.
66
The IR spectra of samples 3 and 4 from field laboratory bag 2 are similar and they
correspond to known IR spectrum of aniline.
Figure 19. IR spectrum of aniline from http://webbook.nist.gov/chemistry, (accessed
3.1.2008).
5. Unknown sample 5
Figure 20. IR spectrum of unknown sample 5, from laboratory bag 2.
67
Given the IR spectrum, pH and smell, we can conclude that chemical 5 from
laboratory bag 2 is an acetic acid.
6. Unknown sample 6
Figure 21. IR spectrum of unknown sample 6, from laboratory bag 2.
The IR spectrum of chemical 6 from laboratory bag 2 is very similar to the IR spectra
of readymade reagent for testing diesel oil (Figure 1, 4 and 11). It contains acetic acid
and aniline.
7. Unknown sample 7
68
Figure 22. IR spectrum of unknown sample 7, from laboratory bag 2.
8. Unknown sample 8
Figure 23. IR spectrum of unknown sample 8, from laboratory bag 2.
69
Based on the IR spectra, chemicals 7 and 8 from the field laboratory bag can be
identified as aniline.
Mysterious chemical named “siansappi viinan”.
The most intriguing of the chemicals from the Police Museum collection is a bottle
containing dark brown, thick liquid with a label “Siansappi viinan” that can be
translated from Finnish as “Pig’s bile in ethanol”.
Figure 24. IR spectrum of “Siansappi viinan”
interesting point. You can position the text box
For analysing the sample I had at my disposal only IR spectrophotometer and pHanywhere in the document. Use the Text Box Tools
meter. Analysis of IR spectrum was done using a Table of Characteristic IR
tab to change the formatting of the pull quote text
Absorptions (Appendix 4). Characteristic peaks found in the IR spectrum are
box.]
presented in Table 7.
70
Table 7. Characteristic IR absorption for chemical named “Siansappi viinan”.
Frequency, cm-1
Bond
Functional group
3500 - 3200
OH, stretch
alcohols, phenols
3000 - 2850
CH, stretch
alkanes
1600 -1585
CC, stretch
aromatics
1470 -1450
CH, bend
alkanes
1370 - 1350
CH, rock
1250 - 1020
CN, stretch
aliphatic amines (?)
900 - 675
CH
aromatics
The IR analysis cannot answer the question what is in the bottle with the curious
name nor where it was used. Most probably the bottle contains a mixture of alcohol,
amines and possible some fats.
3.4.3. pH measurement
For additional technical information, pH of samples of chemicals taken from the field
laboratory bags were measured using Wissenschaftlich-Technische-Werstättem pH
330, electrode SenTex 41. Only chemicals from the laboratory bags were measured
because most of them were unknown, and based on the IR-spectra, they were
mixtures of two organic compounds: aniline and acetic acid. Information on the pH of
chemicals confirmed the presence or absence of acetic acid.
The pH of other chemicals received from the Technical Department of the Police in
Helsinki was not necessary because their identification was complete for all except
one (siansappi viinan). Tables 8 and 9 present results of pH measurements.
Table 8. pH of chemicals from field laboratory bag A.
Sample
1. Unknown
2. Unknown, on the label “reagenssi”
pH
2,0
2,38
71
3. Unknown
4. Unknown
5. Unknown on the label “jääetikka”
2,22
6,5
1,88
Table 9. pH of chemicals from field laboratory bag B.
Sample
1. Acetic Acid, “Etikkahappo”
2. Unknown
3. Aniline
4. Aniline
5. Acetic Acid, “Etikkahappo 1987”
6. Unknown
7. Aniline
8. Aniline
pH
1,02
2,10
6,77
6,87
0,89
0,97
7,77
7,34
3.4.4. X-Ray Fluorescence Spectroscopy
A well-established method of quantitative element analysis is non-destructive X-ray
fluorescence method XRF. The method was used to analyse elements in solid
chemicals received from the Technical Department of the Police in Helsinki. The Xray fluorescence analysis confirmed the presence of elements in the chemicals
studied and complemented the analysis by IR spectrometry. Table 10 presents
results of the X-ray fluorescence of chemicals. The chemicals present in the collection
in more than one sample were not measured because their IR spectra analysis
confirmed their identification.
Table 10 presents the X-ray fluorescence analysis of the solid chemicals from the
Police Museum collection. The method of analysis is very sensitive and can detect
parts-per-million (ppm), for this reason the results reveal unexpected elements.
Those elements are most probably contamination of the sample.
72
Table 10. Results of X-ray fluorescence analysis for solid chemicals from the Police
Museum.
Sample
1. Anthracene
2. Zinc Silicate
3. Silver Nitrate
4. 1-Naphtylamine4sulphonic Acid
10. Malachite-Green
Elements detected by XRF
K
848
Mn 153
Fe 341
Ca 3101
K 13500
S
>10 %
P
>10 %
Ba 6030
Cr
665
Mn
762
Fe 1117
Zn
>10 %
Pb
225
Sr
332
Mo
753
Ag 46434
J
222
K
79458
S
16108
P
49105
Cr
55
Mn
109
Fe
109
Ni
415
Cu
75
Pb
40
Sr
19
Zr
48
Mo
122
Sn
4355
S
27212
Cr
37
Mn
86
Fe
110
K
392
Cr
38
Mn
72
73
11. a. Fuchsine
14. c. Iodine
Fe
Cu
K
Cl
Cr
Mn
Fe
J
Ba
Mn
Fe
Ni
979
575
816
31265
47
93
1156
14076
330
133
203
598
3.4.5. Smell
One of the chemical properties that can be useful, but not always trustworthy, for
identification of chemical substances is their smell. The characteristic, recognizable
smell of vinegar, gasoline or ethanol can indicate the presence of those substances
or their derivatives. However, when sniffing the sample we have to be very careful so
as not to expose ourselves to a dangerous or unpleasant experience. The best way
is to do it in a ventilation hut or well ventilated space while waving delicately over the
open chemical container so that only a very small amount of vapors reaches the
nose. We should never try to smell chemicals that are labelled with warning signs
(danger, poison, explosive etc.)
The characteristic smell for some chemicals was useful in recognizing substances
from the Police Museum collection, especially unknown, unlabelled chemicals from
the field laboratory bags. Two kind chemicals were identified in these bags – acetic
acid and aniline. They were ingredients of a reagent used for testing diesel oil that
was prepared just before the police patrols went into action or possibly even in the
field. Police officers used any available containers and often forgot to label them. For
this reason there were several bottles with unknown substances. Some of the bottles
74
were labelled acetic acid even though the liquid was dark brown.
Some had a
vinegary smell while others, similar in colour, did not. In some samples a strong
gasoline smell could be recognized. Smell indicated the presence of chemicals that
otherwise might not be expected. Smell observations (Table 3 and 4) were confirmed
by IR spectrographic analysis.
3.4.6. Interpretation of research results
IR spectrography confirmed the presence of the chemicals named on the container’s
label or suspected. For unknown substances from the field bags, IR spectrography
and pH measurement were enough to identify the chemical.
Interpretating of the X-Ray Fluorescence results was sometimes difficult especially for
zinc silicate and silver nitrate where many elements could be recognized. This could
probably be explained by sample contamination. The same explanation comes to
mind when looking at results for Fuchsine or Malachite Green, whose chemical
formulas do not explain the presence of so many elements.
The one chemical that should be further tested is “siansappi viinan”. The chemical is
organic and gas chromatography analysis would reveal its contents.
3.5. Active and preventive conservation of chemicals from the Police Museum in
Tampere
For chemicals from the Police Museum collection both active and preventive
conservation was executed. The active conservation was applied only to the
chemicals’ containers. In active conservation two steps were taken. One was
conserving the containers of the chemicals and their labels. This conservation was
mainly done by gently cleaning the glass containers. At first dust was removed using
a microfibre cloth and then the containers’ surfaces were wiped with cotton wool and
ethanol. Paper labels were cleaned with chemical rubber cleaner - soft Wishab
sponge (Lascaux). Paper labels that were damaged were supported with thin
Japanese paper using wheat starch glue.
75
Active conservation can include taking samples of all chemicals present in the
collection and their identification by instrumental methods.
Preventive conservation was done for all chemicals based on the results of
identification analysis and literature. Very helpful in preventive conservation were
material safety data sheets (MSDS). Material safety data sheets are made for most
chemical substances. They contain data regarding the chemical and physical
properties of the substance. They also provide information on procedures for safe
handling and storage. Toxicity, reactivity, health effects and other information about
possible hazards are provided as well.
Material safety data sheets are made specifically for chemicals that are produced and
commonly used in nowadays. For mixtures of chemicals and for older chemicals there
may not be a material safety data sheet. The aging process of chemicals and
possible changes in the chemicals should also be taken into consideration when
using MSDS.
The chemicals from the Police Museum collection are relatively new (about 70 years
old) and for all of them except mixtures MSDS could be found. Based on the
information from material safety data sheet decisions about storage or disposal of
chemicals were made.
3.6. Literature research of chemical and physical behaviours of chemicals the from
Police Museum
Most information about the behaviour of the chemicals from the Police Museum
collection was obtained from the material safety data sheets. In the conservation
report, the MSDS for all stored, pure chemicals were included. Other information
about possible reactions between chemicals that may occur in extreme conditions in
a museum, when chemical containers are broken or chemicals spill could be studied
76
on
an
interesting
website
provided
by
the
U.S.
Department
of
Energy
(http://www.hss.doe.gov/healthsafety/wshp/chem_safety/, viewed 6.1.2008).
3.7. Decision-making
When the chemicals in a collection are identified and their chemical and physical
properties are known, then the most difficult and responsible process of decision
making starts.
Part one of this study discussed why the chemicals in museum collections should be
conserved and preserved. They are historical evidence of our past that should be
studied and preserved. They are the real things from the past that museum visitors
come to see.
For these reasons chemicals and not only their containers should be preserved
whenever possible.
In making decisions about preserving chemicals in museum collections many aspects
should be taken into consideration. The prime concern should always be the safety of
people, museum staff and visitors. For these reasons, chemicals that can explode,
burn, release dangerous vapors or are toxic should not be stored or exposed in
museums. Preservation in museum facilities of chemicals that are acidic, corrosive,
reactive or hazardous in other ways to people and other museum objects is
questionable. Only separate storage rooms and qualified staff should take care of
storing these types of chemicals. Exhibiting them would be very difficult and many
safety procedures would have to be undertaken.
Many hazardous chemicals like acids or solvents are well known and easy to find on
the market. Their production is well documented and therefore their historical value is
not high. However, they pose a high risk to museum staff, visitors and to other
artefacts in the museum collection. In this situation it is better to remove such
chemicals from the collection. Their containers, however, can be preserved after their
content has been removed.
77
Chemicals that are unknown and unlabelled should also be disposed for safety
reasons.
If an unknown chemical is unique or is historically important, further
investigation and research should be done to analyse and describe the artefact.
The chemicals that have been identified and whose chemical and physical properties
are known and reactivity predictable, preventive conservation should be performed.
They have to be stored or exhibited under correct conditions in which they are most
stable.
Taking into consideration all the above aspects of storing and exhibiting chemicals,
decisions concerning the preservation of chemicals from the Police Museum were
made.
The biggest problems were with the chemicals from the field laboratory bags. There
were only two chemicals: aniline, acetic acid and their mixtures, some of them were
not labeled. Samples of gasoline were found in the bags as well. The chemicals from
the field laboratory bags are listed in Tables 3 and 4. Both chemicals are hazardous
and both are typical laboratory chemicals that are commonly produced and used.
They were carried in the laboratory bags together with other artifacts used for testing
diesel oil by the traffic police. Storing those hazardous chemicals, one of which is a
concentrated organic acid and other is a poison, jeopardizes other artefacts in the
bags and indeed the bags themselves. Those two arguments prevailed in the
decision-making and acetic acid, aniline and their mixtures were disposed of.
Samples that contained gasoline were disposed of as well for the same safety
reasons.
The field laboratory bags will be on show in the permanent exhibition in the Police
Museum. It is possible that for aesthetic and educational reasons neutral liquids with
similar colours will be placed in the containers.
78
In Table 2 are chemicals that were obtained by the Police Museum from Helsinki
Technical Department of Police. Most of the chemicals are not dangerous. However,
four of them were disposed of: anthracene, acetone, iodine and iodine solution.
Anthracene’s toxic properties have not been fully investigated, but it is known that
anthracene is very dangerous to the environment. It can also cause irritation to skin
and eyes. The amount of anthracene in the Police Museum collection was quite large
(about 0,5 kg) and for this reason deaccession was decided on.
Acetone was removed from the museum collection due to its flammability.
Iodine is toxic to people and hazardous to the environment. It has the ability to
sublimate and colour surfaces dark brown. For these reasons and also because it is a
common laboratory chemical iodine was removed from the collection. For these same
reasons iodine solution was disposed of.
3.7.1. Disposal
The Police Museum does not have chemicals in their collecting plans and for this
reason and the reasons presented in Chapter 2.9.6. some of the chemicals were
disposed of. Chemicals on which a decision about disposal was made were carefully
removed from their containers and placed into other disposable glass containers that
were labelled. The chemicals’ containers were cleaned of all residues of the
chemicals with appropriate solvents and after that washed with water and Mini Risk
soap, rinsed and dried. The solvents used for washing the containers and soap-water
were gathered in labelled bottles as well.
All chemicals and solvents used for rinsing and washing containers were taken to
hazardous waste facilities – Ekokem Oy Ab, Riihimäki.
3.7.2. Storage
79
The chemicals that were not considered dangerous or hazardous at normal
temperature and pressure were placed in storage. For storing chemicals two
polypropylene boxes with tight lids were prepared. On the bottom of the boxes is a
plate made of 5 cm thick polyethylene foam – Ethafoam (Dow Chemical Company)
where openings in the shape of stored chemicals’ containers were cut. The chemicals
in their original containers were placed in the tightly cut openings. The boxes with
chemicals are stored separately from other museum artefacts in a dark airconditioned storeroom at 18°C.
Photo 8. Chemicals from the Police
Museum
in
Tampere
packed
for
storage using Ethafoam to keep the
bottles safely in place.
Photo 9. Chemicals from the Police Museum in Tampere packed for storage.
80
4. How to preserve chemicals in museum collections
This section of the thesis describes guidelines for the conservation and preservation
of chemical substances. The author of the thesis acknowledges that specific rules
regarding the conservation of chemicals are impossible to list in this document due to
the wide variety of substances.
In his work, “Contemporary Theory of Conservation”, Vinas describes a revolution of
common sense in conservation. He calls for gentle decisions and sensible actions.
(Vinas, 2005 pp 212 - 214).
Similar attitudes are crucial especially in the conservation of chemical collections.
4.1. Preventive conservation of chemical substances in a museum
There is extensive information available regarding the hazards of chemical
substances and about safety precautions, but relatively little information about their
conservation and maintenance. In most cases conservation of chemicals in museum
collections will be limited to preventive conservation only.
According to the American Institute for the Conservation of Historic and Artistic
Works, preventive conservation is the mitigation of deterioration and damage to
cultural property through the formulation and implementation of policies and
procedures for the following: appropriate environmental conditions; handling and
maintenance procedures for storage, exhibition, packing, transport, and use;
integrated pest management; emergency preparedness and response.
Preventive conservation is an ongoing process that continues throughout the life of
cultural property, and does not end with interventive treatment. Preventive
conservation is not only cheaper in the long term but also ethically preferable.
The preventive approach is particularly appropriate for collections that contain
chemical substances, because the introduction of treatment that entails using some
81
other materials such as water, adhesives, consolidants etc., could possibly
compromise an artefact’s research potential.
The conservation of chemical substances is mostly limited to preventive conservation
because of the technical limitations. The aim is to slow down the aging process and
deterioration of chemicals as well as to provide them with a safe environment in which
their chemical content and physical properties will not change. The preventive
conservation of chemicals should also be reviewed with regard to other artefacts in
the museum collection. Safely stored and exhibited chemicals will not pose a danger
to other artefacts in the collection. The primary duty of a museum in which there is a
collection of chemical substances is to care for the safety of the staff and the public.
Effective policies and procedures must be developed and implemented to ensure the
safety of people.
4.2. Standards for collecting and preserving chemicals
Every museum should have written standards for collecting and preserving objects.
Those standards should explain why the museum collects particular groups of
artefacts and guide museum staff in their work. It will also help in making decisions as
to whether to include some object in the museum collection.
The collecting of chemicals needs special standards and guidance for the museum
staff and should be carefully considered because of the danger that some chemicals
can cause to people and the rest of the museum collection. Chemicals in the museum
may be a part of the large collection that concerns a part of our history, like, for
example, police museums or medicine museums. Chemicals may also be the only
objects in the collection as, for example, in pharmacy museums.
4.2.1. Legal possession of chemicals
A museum should not only be legally entitled to store chemicals but also possess all
the required licenses and permits. The legality of some chemicals may vary between
82
countries. Chemicals for whose possession special permission is required are not
only illegal drugs, dangerous poisons or radioactive materials, but can also be pure
ethanol (98%). For example, in Finland permission from the Social and Health Care
Product Control Centre (Sosiaali- ja terveydenhuollon tuotevalvontakeskus) is
required for the possession and use of strong, not denatured ethanol.
4.2.2. Safety of the museum
Museums can collect only chemical substances that they have the facilities and
expertise to care for. If the museum does not have appropriately qualified and
experienced staff it should not hold artefacts that contain dangerous or in other ways
critical chemical substances, but transfer them to a museum that has specialized
facilities and qualified staff. In cases where this is not possible, the museum should
consider disposing of critical chemicals for safety reasons. When human life or health
is in question the priorities are clear.
Chemicals that are considered safe for human life may harm other artefacts in the
collection and their storage and possible exhibition must be carefully planned.
Evaporation and spilling of chemicals and the consequences of this should be taken
into consideration when planning the storage and exhibition of chemical substances.
There may be unstable substances in museums that are not dangerous and can be
safely stored. A good example of this kind of chemical is sugar. Sugar hydrolyzes
very easily, converting sucrose into syrup of fructose and glucose and changing
colour. Unstable chemicals should be stored in proper environments and checked
frequently to prevent damage. Expert attention should be paid to any chemical
problems occurring during the storage or exhibition of chemical substances. Any
conservation treatment, whether active or preventive, should be discussed with
professionals and well documented.
Chemical substances in museums may hold interest for researchers and therefore
there should be an option for non-destructive research on chemicals after getting
approval from the museum curator. (Paine. 1992, pp.13-23).
83
4.2.2.1. Health and Safety Policy concerning collection of chemicals
Museums with collections of chemicals should make clear and well-known policies
concerning the health and safety of the personnel and visitors. This document should
provide common sense guidance for carrying out museum work on the chemical
collection. The document should minimize any risk to the health and safety of the
museum’s staff and ensure that objects are stored, handled, and transported safely.
The document should contain the following information:
1. First Aid
The information and contact information of the person in the museum who has
qualifications to give first aid if required.
2. Policy about working alone
When working alone other colleagues from the museum should know where
you are and how long your work will take. A person who works alone should
not take any risky actions or do work that requires more than one person.
3. Use of equipment and tools
No equipment or tools should be used without training.
4. General guidelines for museum staff
-
No food during work
-
Careful and gentle handling of objects using both hands
-
Use gloves and, if necessary, protective clothing when handling chemical
substances.
-
Chemicals from the collection can be handled and conserved only in
specialized facilities with good ventilation.
-
Moving the chemical substances from one place to another should be well
planned. The weight of the object, its size, hazardous notes and storage
recommendations should be checked.
-
Exposure to any harmful chemical substances should be minimized. The
chemicals must not be open unless necessary, especially if unlabelled. Do not
touch your eyes or mouth after handling chemical substances and always
wash your hands carefully after work.
84
-
Chemicals should be packed safely with appropriate padding, so they will not
spill and their containers will not break.
-
If you feel unwell and suspect that it is because of physical contact with a
chemical substance, seek medical advice immediately.
-
Never dispose of chemical substances by washing them down the sink or
putting them into the garbage.
This draft of the Health and Safety Policy for collections of chemicals was made
based on the policy used in the Museum of the Royal Pharmaceutical Society in
London. (Hudson 2005).
This is only a draft that can be a basis for local policymaking where the needs and
problems of the particular collection are considered.
4.2.3. Disposal of chemical substances
Disposal is the permanent removal of the artefact, or part of it, from the museum’s
collection by any means. It may be sold, exchanged or donated to another museum. It
can also be destroyed. Disposal of the artefact is the most radical and final step that a
museum can take. The disposal from the collection of chemical substances that may
be poisonous or hazardous should be done with a conservator and the authorities of
the Regional Solid Waste Management present (Ongelmajätehuolto) . Before making
the decision, a full assessment of the artefact should be made. If the chemical is of
unknown origin, the museum should consider the possibility that other information
about the chemical may become available later.
For chemical substances, often only the chemical and not its container are disposed
off. This procedure often requires special facilities and special safety procedures
because of the possible danger posed by the removed chemical. (Paine 1992, pp 13 23).
85
4.3. Advice on the preservation of chemicals
In the chapters above, it was mentioned that a museum is not the best place to
preserve unknown, unstable or hazardous chemicals because it does not have
specialized facilities and schooled professionals. Only carefully bottled chemicals that
are well sealed to prevent possible reactions with oxygen and moisture are safe to
store in the museum. Stable chemicals, if carefully stored, can be preserved for many
years. According to Lin of the MDPI Samples Preservation and Exchange Project,
many pharmaceutical companies have properly archived organic samples that were
prepared more than fifty years ago but still are usable and can be used for their
primary purpose. (Lin, 2005).
It is certain that stable chemicals, particularly organic compounds, can be stored at
room temperature without undergoing any chemical changes.
4.3.1. Active conservation of chemicals
Active conservation of chemicals is mostly limited to cleaning the container.
Sometimes, if we know the chemical’s properties and we have the facilities to do it,
the cleaning of the chemical itself is possible. If the chemical contains visible
impurities like pieces of cork floating in the liquid, removing them can be done by
filtration. Some impurities may catalyse chemical reactions and if possible it is better
to remove them from the chemical.
Restoration is often part of the conservator’s work and is done for aesthetic or
educational reasons, especially for artefacts that are exhibited. Chemicals that had to
be removed from their containers and disposed of due to hazardous nature can be
restored by placing a neutral substance reminiscent the original one in the container.
If the conservation of furniture with a broken leg required reconstruction of that leg to
make the furniture more aesthetic and informative, then placing a replica of the
dangerous chemical substance plays the same role. This should be mentioned in the
description of the object.
86
4.3.2. Preventive conservation of chemicals
One of the first steps in planning preventive conservation for the collection of
chemicals is survey of the collection and long-term monitoring. In the preventive
conservation of chemicals we have to consider all factors that can affect chemicals
during their storage or possible exhibition. As for other artefacts in the museum
collection, the four most important factors can affect chemicals: temperature, light,
moisture and oxygen. Control of temperature and moisture is costly but possible with
air-conditioning systems. Oxygen sensitive chemicals should be stored with oxygen
absorbers. One of the most used in museum collections is Ageless® oxygen
scavenger (Mitsubishi). (Day 2005, pp.426-433)
Safe containers for chemicals provide good protection against other environmental
factors like inner pollutants. They can also restrict the vapor of the chemical that
otherwise would become an inner pollutant for the rest of the collection. For example,
carboxylic acid emissions from cabinets and other storage materials can result in
alteration of the salts of weak acids like borates or carbonates. Carboxylic acid
emission can also increase the corrosion of non-noble metallic salts. Other metals like
silver, copper and mercury are sensitive to reduced sulphur gases. Vapors of mercury
that can often be found in museum collection as a part of chemical collection or part
of the different types measuring instruments are particularly dangerous. It is not only
dangerous to people, but also to metals. All metallic elements except iron are capable
of forming amalgams with mercury. (Waller 1999, pp.113–18).
The criteria for good a chemical container are: stable materials and effective closure.
Most of the chemicals come to the museum collection in various glass containers.
Glass is very stable for most chemicals. For a chemical sensitive to light, tinted glass
containers should be used or such a of chemical should be placed in other containers
that can provide light protection.
87
According to Kontradas of theNational Museum of American History, older, cork-top
or glass-top containers are often more secure and stable than new ones from the
1960s or 1970s. (Kondratas 1991, pp 55 – 62).
Below we describe the properties of some containers most often used for chemicals.
4.3.2.1.
Screw-top containers
The tops of the containers can be made of different materials and their stability may
vary. They can be made of metal or plastic.
The best sealing properties have screw tops made of polypropylene with polyethylene
inner liner (Photo 10). Those polymers (PP and PE) are stable with most chemicals.
Only hot aromatic hydrocarbons or chlorinated hydrocarbon solvents can affect
polypropylene and polyethylene. For the liner polyethylene terephthalate (PET), for
example Melinex®, can also be used. Tops made of polypropylene may sometimes
be discolored over time and under the effect of some chemicals, like for example,
iodine. (Suzumoto 1995, pp. 217- 220).
Photo 10. Chemical from the
Police Museum in Tampere.
Bottle
with
screw-top.
polypropylene
88
4.3.2.2.
Ground glass jars
Old chemical jars were often closed with a ground glass top (Photo 11). Such tops
were made of a carefully matched glass stopper with a sealing surface ground to a
fine roughness, mated with a glass vessel with finely ground surface on the
container’s inside neck. Ground glass tops are often not very tight and some kind of
sealing compound like grease or wax must be applied. This may cause contamination
of the stored chemicals. Other problems with ground glass tops are that they often get
stuck so that opening can be very difficult or sometimes impossible.
In containers with ground glass tops liquid chemicals or easily evaporating chemicals
are prone to evaporation of insufficient sealing and can cause damage when spilled.
Solid chemicals can be safely stored in this type of jars if great care is taken not to
contaminate the chemical with a sealing compound. (Clark, 1995, p.221).
Photo 11. Chemical substance
from the Police Museum in
Tampere. Glass container with
ground glass stopper.
89
4.3.2.3
Bail-top containers
Bail-top containers have a gauge wire and cam mechanism to lock down a glass lid
with a rubber gasket. The sealing properties of this type of lid are very good, however
the rubber gasket may be affected by some chemicals, becoming brittle and impairing
the efficiency of the seal. The rubber gaskets should be checked frequently to avoid
leakage or evaporation of chemicals. (Suzumoto 1995, pp. 217- 220).
Photo 12. Bail-top jar.
4.3.2.4.
Metal lids
Metal lids or screw tops are usually made of steel and are often plated with brass
inside and painted. All metal lids and tops will eventually corrode, usually rusting from
the inside out. This will occur if the chemical stored in the container contains water,
alcohol, formaldehyde etc. Dust settling on the lid in high humidity makes very good
conditions for external rust to form. Metal lids and tops often have cardboard liner that
can be easily damaged or shrink and cause evaporation or leakage. The metal lid or
top can be tightened by changing the liner to polyethylene film or foam. If this does
not give sufficient tightness because of the lid damage, changing the lid to
polypropylene should be considered. (Suzumoto 1995 pp. 217- 220).
4.3.2.5.
Bakelite resin lids
Lids and tops made of bakelite resins are almost always black or dark in colour with a
hard smooth surface. Some chemicals that contain alcohol may embrittle the bakelite.
90
Another problem with bakelite is that it has a different expansion-contraction rate from
glass and changes in temperature over time will loosen the lid. This will cause
evaporation or spilling problems. To tighten the bakelite lid inner liner made of
polyethylene foam or polyethylene terephthalate film should be added.
Photo 13. Chemical substance
from the Police Museum in
Tampere. Glass container with
bakelite screw-top.
4.3.2.6.
Double-container system
Chemicals that are very volatile can be placed in a double-container. The same
system can be used when the chemical’s container is not tight but has historical value
and is not to be deaccessed. The double-container system allows the integrity of the
object to be preserved without removing the chemical to another container and
preserving the object (the chemical and its container) separately.
The double-container system consists of two jars. One, the inner, is the original
chemical’s container that is placed in a larger glass jar. On the bottom of the larger
container polyethylene foam is placed (for example: Ethafoam). In the foam an
opening of the size of the bottom of the chemical’s container is cut. This will ensure
that the chemical’s container is kept in place. If the chemical’s container is large or
91
heavy, another ring made of polyethylene foam can be placed in the upper part of the
outer container. (Gisbert 1995, pp. 225-226).
Figure 25. Double-container system with two supporting rings
of polyethylene foam. (Gisbert 1995, pp. 225-226).
The double-container system is recommended for use with all chemicals in the
museum collection. It is the safest way to store them packed in tight stable containers
that can protect museum staff from possible dangerous vapors and artefacts from the
of chemicals stored in the same place. At the same time the chemicals are protected
from environmental factors that can cause damage.
Photos 8 and 9 show a packing system used in the Police Museum in Tampere.
Chemicals after survey, research, and conservation are placed in tightly closed
polypropylene boxes. On the bottom of the boxes is polyethylene foam with openings
where bottles of chemicals are placed. Chemicals packed in this way are stored at
room temperature on a separate shelf in the museum’s store room.
4.4. How chemicals are preserved in museums – a survey
To gather information about the management and conservation of chemicals, an
inquiry was sent to several museums that tend to collect chemical substances. The
inquiry was sent to pharmacy museums, police museums and war museum around
the world. Answers, mostly from the curators, help us see how museums are dealing
with problems that are caused by unusual historical objects in their collections.
The practices are different and very often dictated by practical, physical and financial
constraints.
92
For police museums, where chemicals are only a small part of the collection,
conservation is often limited to storing the chemicals in a stable environment or
disposing of them. The Netherlands Police Museum has a lot of items related to crime
scene investigation that are sometimes not identified. The museum decided that
tubes filled with fingerprinting ink and powders for fingerprint lifting will be preserved
in their original containers but all other types of chemical fluids will be disposed of.
(Breukers 2006).
The Justice and Police Museum in Sydney also has some chemicals and forensic
samples that are kept in their original glass or plastic containers in dry, dark and cool
storage, wrapped in acid free tissue and bubble-wrap. (Ridley. 2006).
Other police museums, like the Police Museum in Belfast or the New York Police
Museum that only have a few chemicals in their collection preserve them in the same
way as other objects, checking only their toxicity. (Brockner, 2006) and (Forrester,
2006).
Pharmacy and medicine museums have to deal with a large collection of chemical
substances of various origins: plant, mineral, animal and synthetic.
A very large and original collection of chemicals is located at the Niagara Apothecary
Museum that dates from 1820.
All chemicals except substances that contain
narcotics are stored in their original containers in the exhibition. The controlled
chemicals or drugs, regardless of potency, were disposed of. The nineteenth century
bottles and jars are placed on the shelves and packages of drugs and chemicals,
mostly unsealed, are stored in bins and drawers below as in their time. For details on
storage and possible conservation of chemicals the museum staff uses the Merck
Index as a reference. The first edition of this appeared in 1889 and publication
continues to the present. (Stieb, 2006).
93
In Albany College of Pharmacy, in the Throop Pharmacy Museum, Material Safety
Data Sheets are used as references for providing a safe environment for chemicals.
(Obos, 2006).
Most pharmacy museums, like for example Deutsches Apotheken-Museum or
Helsinki University museum Arppeanum store their chemicals in the original
containers, providing them with a stable environment. There is concern if something
else should be done to safely preserve their collection of chemicals. (Sinisalo 2006);
(Huwer, 2006).
Below are some chemicals in museum exhibitions. The photos were made in war
museums during the author’s travels in France, 2007.
The different approaches and concerns about chemicals as museum objects can be
seen in these few museums.
Photo 14. Empty chemical bottles in old display cabinets.
Medical History Museum. Rouen, France.
Flaubert Museum and
94
Photo
15.
Bottle
with
an
unknown chemical substance.
Flaubert Museum and Medical
History
Museum.
Rouen,
France.
Photo
16.
Empty
medicine
bottles. Flaubert Museum and
Medical
History
Rouen, France.
Museum.
95
Photo 17. Mercury placed in a glass bottle with a metal screw top. Flaubert Museum
and Medical History Museum. Rouen, France.
Photo 18. Medicine case with
medicines
still
in
place
in
original containers. Equipment
of
the
US
Army,
WWII.
Airborne Museum at SaintMere-Eglise, France.
96
Photo 19. Capsules of morphine used by US Army medics during WWII. The
capsules are empty. Airborne Museum at Saint-Mere-Eglise, France.
Photo 20. Bottles with chemicals used in a US Army field hospital during WWII. The
chemicals are in their glass containers with damaged rubber tops. Airborne Museum
at Saint-Mere-Eglise, France.
97
Photo 21. Chemicals from a
German
field
hospital
from
WWI, near Verdun. Chemicals
unearthed
and
placed
display.
Ossuarive
on
de
Douaumont at Verdun, France.
Photo 22. Chemicals from a
German
field
hospital
from
WWI, near Verdun. Chemicals
unearthed
and
placed
display.
Ossuarive
on
de
Douaumont at Verdun, France.
Photo 23. Chemicals from a
German
field
hospital
from
WWI, near Verdun. Chemicals
unearthed
and
placed
display.
Ossuarive
on
de
Douaumont at Verdun, France.
98
5. Conclusions
The primary concerns of a conservator should be the preservation and care of
historical objects, whether a painting of renown or bottle of a paraffin from the 1950s.
A museum object’s integrity and condition provides historical information and helps us
interpret our history and culture. It is the conservator’s responsibility to preserve an
object, including chemical substances, in the condition that will convey the most
historical meaning and knowledge for posterity.
Chemicals as museum objects evoke concern and even fear in many museum
professionals and their first reaction is to flush them down the sink or pack them
tightly, place them in storage and forget about them.
Chemicals, however, have a very important role in understanding the chemical and
medical history of our society. Therefore guidelines for responsible preservation and
exhibition chemicals should be created.
The first step, as for other objects in a museum, is identification. The information
about known chemicals can be found in different sources, such as the MSDS
(Material Safety Data Sheet) or the Merck Index. Those sources give information
about chemical and physical properties, possible toxicity and other health concerns,
as well as handling and storage advice. Sometimes information is hard to find if the
chemical substance contains many ingredients, making its toxicity and stability
difficult to predict.
The safest way to preserve and conserve chemicals is always common sense,
especially when dealing with hazardous materials. The primary concern must always
be human well-being and the preservation of dangerous substances is only possible if
the museum has specialized facilities and a qualified staff. Otherwise it is better to
give the critical objects to other museums that have the capability to preserve it. The
last resort is disposal. This has to be done by the Regional Hazardous Waste
99
Management. The decision for disposal should be weighed carefully and the chemical
well documented.
Museums that have a collection of chemicals should make precise safety polices and
guidelines for the storage and handling of chemicals.
Chemicals from the Police Museum were identified and after that a proper storage
solution was devised for them. The Police Museum does not have safe facilities for
storing hazardous and toxic chemicals and for this reason some of the chemicals
were disposed of. The chemicals that were disposed of were chemicals produced in
large quantities today with no special historical value, but their dangerous properties
could have caused problems for the museum staff and posed a danger to other
objects in the collection.
100
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105
Table of Figures
Figure 1. EU standard toxic symbol, as defined by Directive 67/548/EEC.
Figure 2. Modes of oxygen uptake versus time (according to Feller 1994).
Figure 3. Triple point of three existing phases.
Figure 4. Preservation Calculator
Figure 5. Electromagnetic spectrum.
Figure 6. IR spectrum of unknown sample 1 from laboratory bag 1.
Figure 7. IR spectrum of acetic acid.
Figure 8. IR spectrum of aniline.
Figure 9. IR spectrum of unknown sample 2 from laboratory bag 1.
Figure 10. IR spectrum of unknown sample 3, from laboratory bag 1.
Figure 11. IR spectrum of petroleum according to http://search.be.acros.com/
(accessed 2.1.2008).
Figure 12. IR spectrum of unknown sample 4, from laboratory bag 1.
Figure 13. IR spectrum of unknown sample 5, from laboratory bag 1.
Figure 14. IR spectrum of acetic acid from http://search.be.acros.com/, (accessed
2.1.2008).
Figure 15. IR spectrum of unknown sample 1, from laboratory bag 2.
Figure 16. IR spectrum of unknown sample 2, from laboratory bag 2.
Figure 17. IR spectrum of unknown sample 3, from laboratory bag 2.
Figure 18. IR spectrum of unknown sample 4, from laboratory bag 2.
Figure 19. IR spectrum of aniline from http://webbook.nist.gov/chemistry, (accessed
3.1.2008).
Figure 20. IR spectrum of unknown sample 5, from laboratory bag 2.
Figure 21. IR spectrum of unknown sample 6, from laboratory bag 2.
Figure 22. IR spectrum of unknown sample 7, from laboratory bag 2.
Figure 23. IR spectrum of unknown sample 8, from laboratory bag 2.
Figure 24. IR spectrum of “Siansappi viinan”
Figure 25. Double-container system with two supporting rings of polyethylene foam.
(Gisbert 1995).
106
Table of Photos
All photos presented in the thesis were taken by Elzbieta Djupsjöbacka
Photo 1. Ossuarive de Douaumont at Verdun, France. Medical equipment from the
First World War.
Photo. 2. Airborne Museum at Saint-Mere-Eglise, France. Chemicals that were in
American parachutists’equipment.
Photo 3. Memorial Museum at Caen, France. Medical equipment from a German field
hospital.
Photo 4. Damaged container with silver nitrate from the collection of Police Museum.
Photo 5. Bottle of aniline with damaged lid, from the collection of Police Museum.
Photo 6. Field equipment bag of chemicals for testing the purity of gasoline. From the
collection of the Police Museum.
Photo 7. Test tubes with unknown liquid found in one of the mobile police field bags
for testing the purity of gasoline. Police Museum collection.
Photo 8. Chemicals from the Police Museum in Tampere packed for storage using
Ethafoam for keeping bottles safely in place.
Photo 9. Chemicals from the Police Museum in Tampere packed for storage.
Photo 10. Chemical from the Police Museum in Tampere. Bottle with polypropylene
screw-top.
Photo 11. Chemical substance from the Police Museum in Tampere. Glass container
with ground glass stopper.
Photo 12. Bail-top jar.
Photo 13. Chemical substance from the Police Museum in Tampere. Glass container
with bakelite screw-top.
Photo 14. Empty chemical bottles in old display cabinets. Flaubert Museum and
Medical History Museum. Rouen, France.
Photo 15. Bottle with an unknown chemical substance. Flaubert Museum and Medical
History Museum. Rouen, France.
Photo 16. Empty medicine bottles. Flaubert Museum and Medical History Museum.
Rouen, France.
Photo 17. Mercury placed in a glass bottle with a metal screw top. Flaubert Museum
and Medical History Museum. Rouen, France.
Photo 18. Medicine case with medicines still in place in original containers.
Equipment of the US Army, WWII. Airborne Museum at Saint-Mere-Eglise, France.
Photo 19. Capsules of morphine used by US Army medics during WWII. Capsules
are empty. Airborne Museum at Saint-Mere-Eglise, France.
Photo 20. Bottles with chemicals used in a US Army field hospital during WWII. The
chemicals are in their glass containers with damaged rubber tops. Airborne Museum
at Saint-Mere-Eglise, France.
Photo 21. Chemicals from a German field hospital from WWI, near Verdun.
Chemicals unearthed and placed on display. Ossuarive de Douaumont at Verdun,
France.
107
Photo 22.
Chemicals
France.
Photo 23.
Chemicals
France.
Chemicals from a German field hospital from WWI, near Verdun.
unearthed and placed on display. Ossuarive de Douaumont at Verdun,
Chemicals from a German field hospital from WWI, near Verdun.
unearthed and placed on display. Ossuarive de Douaumont at Verdun,
Table of Tables
Table 1. Generic Chemical Interaction Matrix.
Table 2. Most commonly used instrumental analysis methods.
Table 3. Labelled chemicals from Police Museum collection.
Table 4. Chemicals from the Police Technical Department of Helsinki.
Table 5. Chemicals from field laboratory bag A.
Table 6. Chemicals from field laboratory bag B.
Table 7. Characteristic IR absorption for chemical named “Siansappi viinan”.
Table 8. pH of chemicals from field laboratory bag A.
Table 9. pH of chemicals from field laboratory bag B.
Table 10. Results of X-ray fluorescence analysis for solid chemicals from the Police
Museum.
A1-1
Appendix 1. European hazard symbols
(Directive 67/548/EEC)
Oxidizing agent (O) Explosive (E)
Highly flammable (F) Extremely flammable
(F+)
Toxic (T)
Very toxic (T+)
Harmful (Xn)
Corrosive (C)
Dangerous for the environment (N)
Irritant (Xi)
A2-1
Appendix 2. Common hazard symbols
Name
Symbol Unicode Image
Toxic sign
☠
U+2620
Caution sign
☡
U+2621
Radiation sign
☢
U+2622
☣
U+2623
Ionizing radiation sign
Non-ionizing radiation sign
Biohazard sign
A3-1
Appendix 3. IR spectra of chemicals from the collection of the Police Museum in
Tampere and their analysis
1. Antharcene
Chemical formula of anthracene
ATR-IR-spectra of anthracene technical from the collection of the Police
Museum in Tampere
A3-2
2. Zinc Silicate
Zn2SiO4 – chemical formula of zinc silicate
ATR-IR-spectra of zinc silicate from the collection of the Police Museum in
Tampere
A3-3
3. Silver Nitrate,
AgNO3 - chemical formula of silver nitrate
ATR-IR-spectra of silver nitrate from the collection of the Police Museum in
Tampere
IR spectrum of Silver Nitrate according to www.webbook.nist.gov/chemistry
(applied 31.12.2007
A3-4
4. Naphtylamine-4sulphonic Acid
Chemical formula of naphtylamine-4sulphonic acid
ATR-IR-spectra of naphtylamine-4sulphonic acid from the collection of the
Police Museum in Tampere.
IR spectrum of naphtylamine-4sulphonic acid
according to www.webbook.nist.gov/chemistry (accessed 31.12.2007
A3-5
5. Peroxide 3%
ATR-IR-spectra of peroxide 3% from the collection of the Police Museum in
Tampere.
A3-6
6. Paraffin
CnH2n+2 – chemical formula of paraffin
ATR-IR-spectra of paraffin from the collection of the Police Museum in
Tampere.
IR spectrum of paraffin according to www.webbook.nist.gov/chemistry
(accessed 31.12.2007)
A3-7
7. Glycerine
C3H5(OH)3 – chemical formula of glycerine
ATR-IR-spectra of glycerine from the collection of the Police Museum in
Tampere.
IR spectrum of glycerine according to www.webbook.nist.gov/chemistry (accessed
31.12.2007).
A3-8
8. Acetone
CH3COCH3 – chemical formula of acetone
ATR-IR-spectra of acetone from the collection of the Police Museum in
Tampere.
IR spectrum of acetone according to www.webbook.nist.gov/chemistry
(accessed 31.12.2007).
A3-9
9. Neo-Amisept
Neo-Amisept contains: ethanol, isopropanol, glycerine.
ATR-IR-spectra of Neo-Amisept from the collection of the Police Museum in
Tampere.
A3-10
10. Malachite Green
- chemical formula of Malachite Green
ATR-IR-spectra of Malachite Green from the collection of the Police Museum
in Tampere.
IR spectrum of Malachite Green according to www.webbook.nist.gov/chemistry
(accessed 31.12.2007).
A3-11
11. Fuchsine
- chemical formula of Fuchsine
ATR-IR-spectra of Fuchsine from the collection of the Police Museum in
Tampere.
IR spectrum of Fuchsine according to http://search.be.acros.com/ (accessed
31.12.2007).
A3-12
12. Tetrabromphenolsulfophtalein
chemical formula of etrabromphenolsulphophtalein
ATR-IR-spectra of tetrabromphenolsulphophtalein from the collection of the Police
Museum in Tampere.
IR
spectrum
of
tetrabromphenolsulphophtalein
http://search.be.acros.com/ (accessed 31.12.2007).
according
to
A3-13
13. Clove Oil
ATR-IR-spectra of clove oil from the collection of the Police Museum in Tampere.
IR spectrum of clove oil according to http://www.irug.org/
31.12.2007).
(accessed
A3-14
15. Jodicalium
ATR-IR-spectra of jodicalium from the collection of the Police Museum in
Tampere.
A4-1
Appendix 4. Characteristic IR Absorption by http://orgchem.colorado.edu/
(accessed 2.1.2008)