Mass Deacidification for Libraries and Archives
NEWS
The LIBRARY of CONGRESS
Public Affairs Office
101 Independence Avenue S.E.
Washington, DC 20540-1610
phone (202) 707-2905
fax (202) 707-9199
e-mail pao@loc.gov
www.loc.gov
December 21,2001
Press Contact: Helen Dalrymple (202) 707-1940
Web site:
www.loc.gov
SAVING THE WRITTEN WORD: LIBRARY OF
CONGRESS AWARDS MASS DEACIDIFICATION CONTRACT
The Library has awarded a contract to Pittsburgh-based Preservation Technologies L.P.
(PTLP) that will save 1 million books and at least 5 million manuscript sheets from further acid
deterioration.
This contract, the third awarded to PTLP since 1995, will permit the Library to increase
preservation productivity and save increasing quantities of endangered materials over time. The
contract calls for ramping up treatment during the remaining four years of the contract, FY 2002FY 2005, increasing annual book deacidification from 100,000 to more than 250,000 books per
year by the fifth and final year.
Congress has demonstrated continued support for the Library's plans to save millions of
books and manuscripts by approving funding for this important endeavor.
As the national library and the official library for the U.S. Congress, the Library of
Congress has focused its early mass deacidification efforts primarily on collections of Americana.
The deterioration of acid-containing paper presents a formidable challenge, because this
degradation undermines the use and long-term preservation of library collections and archival
materials worldwide. The Library of Congress has provided leadership over several decades in the
development and evaluation of mass deacidification processes and their application to valuable,
at-risk book collections and other paper-based items to achieve economies of scale.
With strong support from Congress, the Library has worked with Preservation
Technologies under two previous contracts to deacidify more than 400,000 books, using the
Bookkeeper deacidification technology that was pioneered by PTLP. The Bookkeeper process
exposes paper to acid-neutralizing chemicals. Using a suspension of magnesium oxide particles
-over-
to neutralize the acid and leave a protective alkaline reserve, Bookkeeper halts deterioration and
adds hundreds of years to the useful life of paper.
Under the new contract, the Library will continue to provide training and oversight to
PTLP staff who select books for treatment; charge out, pack, and ship volumes to the
deacidification plant in Cranberry Township, Pennsylvania; and then reshelve books following
treatment. Library staff provide contract administration and quality control over the selection
and refiling of books as well as laboratory testing to monitor the effectiveness of treatment.
Library staff have also developed procedures to ensure that information about each deacidified
book is captured in the holdings record in the Library's bibliographic database.
Preservation Technologies has engineered new horizontal treatment cylinders that it uses
to offer deacidification services to libraries and archives for the treatment of loose manuscripts
and other items in unbound formats. The Library's new contract authorizes PTLP to build and
install a horizontal manuscript treater and a Bookkeeper spray booth in a Library building on
Capitol Hill. This will enable the Library to treat large quantities of paper-based materials in
nonbook formats, such as newspapers, manuscripts, maps, music scores, pamphlets, and posters.
Additional information about the Library's mass deacidification program is available on the
Library's Web site at www.loc.gov/preserv/carelc.html or by contacting the Library's
preservation projects director, Kenneth Harris, at (202) 707-1054 or by e-mail at khar@loc.gov.
PR 01-155
12/21/01
ISSN 0731-3527
• Minor damages (e.g., head cap, head, or tail, as well as
minor spine tears and minor hinge or joint damage) are
acceptable -- should be noted on packing lists, to prompt
additional examination by contractor staff
alkaline reserve in order to avoid the destructive testing
(titration) of actual pages from collection books. At LC's
request, the contractor also treats one disposable test book per
week to confirm that the process is working properly. Test
papers and test books are returned each week to LC for
additional laboratory testing.
A further quality control check for alkaline reserve in each batch
of books (8 per batch) is made by dividing the weight of the
batch into the weight of the MgO used to treat it.
All treated books are marked, like the alkaline books left on the
shelf during selection screening, with a white dot on the spine.
A Bookkeeper label is also attached inside the back cover of
each treated book.
Books are mounted in treatment cylinders,
where magnesium oxide is deposited to
neutralize acids in the paper.
Text Block in Good Condition
• No loose or torn pages
• Leaves not overly brittle
• No "blocking" (pages stuck together)
Size Parameters
• 11.5" Height x 9" Depth x 2.5" Thickness = maximum
measurements for treatment in Bookkeeper III equipment
• Larger and heavier books can be treated in horizontal
Bookkeeper equipment or sprayed
QUALITY CONTROLS
T
he deacidification process, utilizing magnesium oxide
(MgO) to neutralize acid in the paper, takes two hours
from the time books are placed in the Bookkeeper
treatment cylinders until the volumes are ready to be packed for
return to their home library. All steps in the process, from
selection to reshelving, are monitored to ensure that the
intended results are achieved.
The Bookkeeper process meets the Library's basic preservation
requirements by:
• raising the pH level of treated paper to the acceptable range
of 6.8 to 10.4 pH
• achieving a minimum alkaline reserve of 1.5%
• extending the useful life of paper (measured by fold
endurance after accelerated aging) by over 300%.
MANUSCRIPT DEACIDIFICATION EQUIPMENT
P
reservation Technologies has developed new equipment
that it is using to offer deacidification services for loose
manuscript and archival materials. The Library is
negotiating with Preservation Technologies to build and install
a horizontal treater
and a Bookkeeper
spray booth in a
Library building on
Capitol Hill, which
would enable LC to
treat on-site paperbased materials in nonbook formats, such as
manuscripts,
maps,
music
scores,
p a mphl et s,
and
posters.
Manuscripts are placed in hanging
files to prepare them for treatment.
ADDITIONAL INFORMATION
information and data about the Library's mass
More
deacidification program are available at the following
Internet address:
http://lcweb.loc.gov/preservcarelc.html
At that site, select "Mass Deacidification Program," then scroll
to the bottom of the page and click on "Mass Deacidification
Publications Online" to access a number of publications about
deacidification activities at the Library.
Surrogate test papers that are inserted in 10% of the treated
batches of books are tested by both LC and the contractor for
[BrochureDeacid.rev.6.2001 .wpd]
LIBRARY SAVES PERMANENTLY VALUABLE BOOKS
Library of Congress, with strong support from the U.S.
TheCongress,
has provided leadership in the development and
books following treatment. After training by Library personnel,
the contractor's onsite workers are overseen by a company
supervisor, and the Library monitors their progress against
contract objectives.
Contractor staff working onsite in LC buildings examine each
book in collections that have been designated by Library
management for deacidification screening. Overly brittle books
are left on the shelf.
evaluation of mass deacidification processes and their
application to valuable book collections and other paper-based
items to achieve economies of scale. Through a competitive
process, the Library negotiated a second contract for mass
deacidification in 1997. The contract was awarded to
Preservation Technologies, Limited Partnership (PTLP) of
Pennsylvania. The company is providing book preservation
services to the Library using the firm's Bookkeeper mass
deacidification process. This contract is an outgrowth of an
earlier limited production contract that enabled the Library to
deacidify books for the first time and to resolve book selection,
shipping, and quality control details of the deacidification
program.
In addition, books
with the following
characteristics are
generally
not
considered
for
deacidification
treatment with the
Bookkeeper
process:
• Text paper is Assessment of paper acidity or alkalinity using a
alkaline or pH pen.
permanent
are books that are deacidified; in both
cases, this mark indicates longevity of the text block)
• Text paper is coated or super-calendered (coated paper is
not a high priority for deacidification, due to its alkaline
coating)
• Title is already available in (or scheduled for) microform or
digital format, or it is a candidate for future reformatting
due to advanced embrittlement of the paper
• Duplicates of a given imprint of a specific title (only one
copy of any given imprint is treated)
LC's "ONE GENERATION" MASS DEACIDIFICATION
PLAN: A NEW MULTI-YEAR CONTRACT
C
ongress demonstrated support for the Library's plan to
save 8.5 million retrospective and new books over a 30
year period by approving Fiscal Year 2001 funding that is
permitting the Library to award a contract to treat 1,000,000
books and at least 5 million manuscript sheets within five years.
The Library plans to ramp up from deacidify ing 100,000 books
in FY2001, increasing the quantity by 50,000 books per year,
until it is treating between 250,000 and 300,000 books annually
in the 5th and successive years of the 30 Year Plan.
LIBRARY "DEMONSTRATION SITE"
the effective operation of its mass deacidification
Given
program for books over the past several years, the
Library is serving as a demonstration site for managers and
technical staffs from other libraries, archives, and cultural
institutions. Anyone interested in learning firsthand about
administrative and work flow procedures required for mass
deacidification programs should contact Kenneth E. Harris,
Preservation Projects Director, Preservation Directorate, Library
of Congress, LM-G21, Washington, DC 20540-4500.
Telephone: (202) 707-1054; Fax: (202) 707-3434; E-mail:
khar@loc.gov.
ON-SITE CONTRACT WORK IN LC BUILDINGS
U
nder contract terms, the vendor is providing onsite
services in Library of Congress buildings. The
company's employees select books for treatment, pack and
ship volumes to the deacidification plant, and reshelve
Each book in a collection is individually examined to decide
whether it is a good candidate for deacidification.
SELECTION CRITERIA AND PROCEDURES
eacidification treatment is reserved for books that are
acidic and at risk of loss if no action it taken. Due to its
role as the national library and the official library of the
U.S. Congress, the Library is focusing primarily on selection of
"Americana" for early treatment under the mass deacidification
program, emphasizing the selection of endangered volumes
from collections that are central to the Library's mission.
Screening and treatment is being undertaken beginning with the
following LC book classes, which have been approved for
deacidification processing by Library administrators,
preservation managers, and the LC Collections Policy
Committee:
D
Class E
American History
:
Class Fl-975
U.S. Local History
Class CS71
U.S. Family History
Classes PZ3&4
Fiction in English
Class PS
American Literature
Class JK
U.S. Political Science
Class KF
U.S. Federal Law
Class PN Americana Literary History and Collections
Most books that are deacidified under the terms of this contract
will be books that are structurally sound enough to be treated in
the vertical Bookkeeper treatment cylinders. However, books
that have limited binding damage (hinge, joint, head, or tail
damage) or are too large for Bookkeeper vertical-cylinder
treatment can be deacidified in other ways by the contractor —
horizontally in manuscript-treatment equipment or sprayed.
Volumes with the following characteristics are considered good
candidates for mass deacidification in the Bookkeeper vertical
book treatment chambers:
Bound Volumes
•
•
•
;
Hardbound books generally treat better; however,
Paperbacks are OK, if they are in good condition and
structurally sound (it is critical to determine whether the
paper is too brittle to withstand treatment and whether the
binding adhesive is too degraded to support the text)
Plasticized covers will not fully absorb the magnesium
oxide and will require wiping off by contractor staff after
treatment
Bindings in Good Condition
;
•
•
No detached covers (boards)
Leather covers with red rot are OK
A
W O R L D
L E A D E R
IN
P A P E R
P R E S E R V A T I O N
PreservationTechnologies
Background information on Bookkeeper® deacidification
Frequently Asked Questions
1.
What is the Bookkeeper deacidification process? The Bookkeeper
process preserves and protects all forms of paper based materials. It
deposits a safe, non-toxic alkaline buffer into the structure of the paper. This
buffer material neutralizes acids that can rapidly weaken the paper and cause
it to become brittle.
2.
What materials can be treated? The Bookkeeper process is suitable for all
paper-based materials, including bound and unbound documents, printed and
handwritten materials, manuscripts, newsprint and periodicals, books, letters
and envelopes, postage stamps and paper collectibles, pamphlets, and flat
stock such as maps and prints. The process uses no solvents and will not
move, feather, loosen, or harm inks, adhesives, covers, leather, plastic,
metals or fabrics.
3.
What are typical treatment results? Materials are treated individually or in
small batches to ensure quality control. The final pH of the paper following
treatment depends on the paper composition prior to treatment. The range of
possible pH results is between 7 and 10, and typical results are in the range
of 8.0 - 9.5. Sufficient alkaline material is added to the paper to provide a
protective alkaline reserve. The typical reserve is equivalent to adding 1.5%
by weight calcium carbonate, or 300 milliequivalents per kilogram.
4.
Is it effective? Treated materials have been tested and compared with
untreated control samples in independent tests conducted by the Library of
Congress, the Institute of Paper Science and Technology (Atlanta), the Image
Permanence Institute (Rochester), the Institut Royal du Patrimoine Artistique
(Belgium), TNO Centre for Paper and Board Research (The Netherlands),
Berner Fachhochschule (Switzerland), and the American Philatelic Society
(State College). Accelerated aging testing shows that treatment by the
Bookkeeper process should extend the usable life of paper based materials
by a factor of at least 3-5 times. Although artificial aging does not exactly
reproduce natural aging effects, the nature of the test is to err on the low side,
and we expect the resultant life extension of treatment will exceed the
predictions of accelerated aging.
Page 1 of 4
5.
Is it safe for manuscripts, colors and inks? The Bookkeeper process
contains no solvents and no water. Independent testing of hundreds of ink and
paper samples from 1870 to now have found no inks or colors which are
dissolved or caused to run or bleed by this material.
In few cases, the shade of a color may be affected by the change in pH from
acid to alkaline. But even pH sensitive colors are often not affected unless the
paper becomes wet with water or in very humid conditions. In general, the
Bookkeeper process should not be used on some "blue prints" or other similar
materials where colors may be affected by raising the pH.
6.
Is it safe for binding materials and adhesives? The process does not
remove moisture from the materials. There is no need to dehydrate materials
before treatment, or to restore moisture or remove odors following treatment.
Thus treatment has no harmful effect on adhesives, metals, plastics, or cover
materials. The process has no observable prompt effect on leather.
Accelerated aging tests on leather have not been made yet.
7.
Is it safe for photographs? The Image Permanence Institute at the
Rochester Institute of Technology tested photographic materials in contact
with treated paper and determined that such an application safely satisfies the
requirements of the Photographic Activity Test (PAT). But the process is not
intended for use on photographs, and photographs will not benefit from the
treatment. Photographs can safely be stored in contact with treated materials
with no adverse effect from the treatment.
8.
9.
Does it stop paper from yellowing? No, papers like newsprint contain
chemical impurities (such as lignin) that are affected by light and oxygen.
_i These will still tend to turn yellow over time. Treatment does not accelerate
this effect, and in some cases may delay the yellowing somewhat.
What about glossy or encapsulated materials? Non-absorbent materials
(such as plastic) can be included in the process without harm, but they will
receive no benefit. The product does not penetrate the plastic coating of
encapsulated materials. A light coating of alkaline material will be noticeable
on the surface. This can be removed with a soft dry cloth or soft bristle brush.
The Bookkeeper process will provide limited benefits for coated paper
materials. This type of paper will absorb less alkaline buffer and will usually
have a light coating on the surface as well. The surface material can be
removed, and the paper will retain some alkaline buffer. Materials that
contain a mix of coated and uncoated stock can be safely treated.
10.
Does the process remove moisture from the materials? The process
does not require a drying step to remove moisture from the paper before
treatment. No moisture is removed following treatment either, and so no posttreatment storage is required for reconditioning of paper.
Page 2 of 4
11.
What is the alkaline buffer? The buffer materials are microscopic particles
of an alkaline compound (magnesium oxide). The particles are dispersed and
suspended in an inert liquid material (a blend of non-toxic fluorinated
materials). This dispersion can be applied by dipping or spraying. In contact
with paper, the alkaline particles attach and blend with the paper structure,
and the inert liquid simply evaporates. Because the formula contains no
water, the liquid does not cause the paper fibers to swell or make the paper
"wet", and it will not cockle or stiffen from the application.
12.
Is the treatment hazardous or polluting in any way? The ingredients in the
Bookkeeper process are non-hazardous, non-toxic, and non-flammable. The
material dries odor-free. Spray products and the processing equipment can
be used in spaces with normal ventilation with no special exhaust
requirements. The materials used have no ozone depleting potential. Both
the treating process and the final result are very safe for people and the
environment.
13.
How is the material processed? In small batches, the materials to be
treated are immersed in the treating bath, and gentle motions of the paper
and liquid are used to help ensure uniform coverage. During this time, the
treating bath is continuously circulated to filter loose dust and dirt from the
paper and to monitor and maintain the proper concentration of treating
materials. Then the treating materials are drained, and the remaining liquid t
evaporates and is recovered in the process. Batches usually take about 2
hours total, and the moisture content of the paper is not affected by the
treatment. Very fragile materials are processed by hand treatment, dipping or
spraying.
How is the alkaline reserve deposited? The alkaline particles deposited
into the structure of the paper are extremely small. Average particle sizes are
on the order of 1 micron. The particles are produced using a technology that
gives them a very large internal surface area, 250 times the absorbing surface
area of a normal particle. The large surface area and small diameter help the
particles penetrate and attach to the cellulose fibers in the paper where they
act like chemical sponges absorbing, trapping, and neutralizing acids.
14.
15.
How does the treatment chemistry neutralize acids? The acids in paper
migrate freely. We see this effect when acidic paper damages adjacent, nonacidic materials. Alkaline buffered folders or boxes holding acidic materials
can become acidic in just a few years time from this effect. Under normal
storage conditions, acid reacts very slowly with cellulose fibers but very
quickly with alkaline materials. The Bookkeeper process takes advantage of
this difference in reaction rates to protect the paper. Within the structure of
the paper, the acids migrate among the cellulose fibers where they are quickly
absorbed and neutralized by the highly absorbent alkaline particles, long
before they have time to react with and weaken the cellulose fibers.
Over the first few weeks following treatment, the magnesium oxide particles
Page 3 of 4
combine with moisture in the air to form magnesium hydroxide, a non-toxic
alkaline buffer. These buffer particles readily absorb and neutralize the acids in
the paper. The material continues to absorb acid over the life of the paper.
16.
Is the treatment permanent? This is a permanent treatment that should not
need to be repeated under normal storage conditions.
17.
Are there any restrictions on materials to be processed? The treating
process is very gentle, but the materials to be treated should be in stable
condition and able to withstand careful handling. Materials in poor repair or
too fragile to handle are usually not considered good candidates for this
treatment because they have little or no strength left to preserve. This
process does not strengthen the paper.
18.
Can raising the pH cause alkaline hydrolysis? No - the maximum pH
achievable using magnesium oxide, 10.4, is well below the value required to
weaken the paper structure in this way. Alkaline hydrolysis occurs at much
higher pH values, at much higher than normal temperatures, in the presence
of excess liquid water.
19.
Is it hazardous in any way? The ingredients in the Bookkeeper process are
non-hazardous, non-toxic, and non-flammable. The material dries odor-free,
and it can be used in spaces with normal ventilation with no special exhaust
requirements.
20.
Is more testing planned? Preservation Technologies has a commitment to
conducting and supporting ongoing research into topics of deacidification. We
are currently sponsoring and planning research by independent agencies
looking at aging paper in polluted environments, aging effects on leather,
aging effects on iron gall ink, aging effects on textiles and artwork, reduced
temperature accelerating aging tests, prompt effects on paper strength and
prompt effects on works of art on paper. Please contact us to discuss details
of these or other projects.
For more information, contact:
North America:
Preservation Technologies, L.P.
111Thomson Park Drive
Cranberry Township, PA 16066
USA
1-724-779-2111 Tel
1-724-779-9808 Fax
info@Dtlp.com
Europe:
Preservation Technologies, B.V.
Pluim-es 18
2925 CM Krimpen a/d Ijssel
The Netherlands
31.0.180.521188 Tel
31.0.180.525400 Fax
info@pUD.com
www.ptlp.com
© 2003 Preservation Technologies, L.P.
Page 4 of 4
Preservation Technologies, L.P.
49 Cherry Street
Warrawee, NSW 2074
Australia
61.2.9487.1795 Tel
61.2.9487.2690 Fax
info@ptlD.com
\ A /hen Andrew Carnegie built his first public library
V Y in 1895, he recognized the importance of making books
available to every citizen. His legacy of free public libraries
continues on today, yet his gift is threatened. Acid harbored in
the paper of millions of books in libraries is causing the pages to
become brittle. Countless documents and books have become so
fragile that they cannot be touched for fear they will fall apart.
Preservation Technologies provides products and services to
preserve collections of distinction for libraries and archives
throughout the world. Bookkeeper® is our breakthrough
deacidification process that neutralizes acids without damaging
books or documents.
i
For the first time, libraries and archives
have a means to stop the deterioration of
their valuable collections.
Preservation Technologies' patented
Bookkeeper,
deacidification process, neutralizes harmful acids and
greatly extends the lifespan of books and documents. Instead
of becoming brittle within decades, materials treated with
the Bookkeeper mass process or spray products will last for
centuries.
Collections at Risk
Books and documents arrive in numbered,
locked document containers.
The United States Library
of Congress estimates that
its collection contains
17,000,000 volumes printed
on acidic paper. More than
100,000 acidic volumes are
being added to the
collection every year.
In 1995, after working for
over twenty years to solve
the problem of acidic paper,
the Library of Congress
awarded the first contract
for mass-deacidification to
Preservation Technologies.
The Safest Process
The Bookkeeper process
differs from less successful
attempts to neutralize acids in
paper because it does not use
any solvents or gasses that can
damage inks, adhesives, paper
or binding fabrics.
Each shipment is assigned a bar code,
indicating client instructions.
2
To a historian, libraries ar
Each item is inspected
and handled with care.
With our process, the
microscopic buffer materials
are dispersed and suspended
in an inert liquid. No pretreatment of paper is required.
Bookkeeper does not remove
Preservation Technologies provides products and services
to preserve collections of distinction throughout the world
moisture from paper and
books — eliminating the risk
of further damage to already
weakened paper.
And because Bookkeeper is
solvent free, no harmful
chemical residues remain in
Oversized illustrated materials are safely
the paper. There is no need
for after-treatment offgassing to remove odors or
humidification to restore
moisture to the paper.
treated
food, shelter, and even muse ...
Bookkeeper treating cylinders.
A Proven Process
Preservation Technologies
offers the safest, most effective
means of deacidification.
Tests show that the buffering
Independent tests conducted
agent is effectively distributed
by leading research laboratories
throughout the sheet of
have verified the safety and
paper, in both bound volumes
effectiveness of the
and single sheets. In this
Bookkeeper process.
research, as well as in actual
practice, no inks were found
to migrate, fade or bleed
during or after treatment.
Individual items are sorted for
appropriate treatment.
Materials treated with Bookkeeper last at least five times
longer than untreated books and documents.
... the library of published
materials
Bookkeeper is the safest process
to neutralize acid in paper.
Item folders of manuscripts
and records are registered
prior to treatment
Manuscripts and
Records
Because of the demonstrated
safety and effectiveness of the
process, Bookkeeper is the
only deacidification method
that can be used with the
wide variety of maps,
manuscripts, printed documents and other paper-based
materials contained in
modern archival collections.
Bookkeeper has passed the
Photographic Activity Test, a
benefit that frees archivists
from worrying about
photographs being harmed if
they are housed in boxes or
folders with papers that have
been deacidified.
Millions of documents have been carefully treated using the Bookkeeper process.
books, pamphlets, periodicals ...
State-of-the-art monitoring insures uniform treatment
and the shortest possible turnaround time.
Safeguarding
Your Collections
Preservation Technologies
has also developed methods
of shipping and handling
archival and library collections
that ensure their integrity
during the entire deacidifica-
After treatment, each
item is inspected and logged for its return
to the client.
6
tion process. Each volume or
document folder is placed
securely in a numbered,
Every volume and document
folder is carefully inspected
and condition is recorded
before and after treatment.
Clients are provided with
locked document container.
Items are removed from
their containers for approximately two hours during
treatment and then placed
reports documenting the pH
and alkaline reserve of test
papers for each order that is
processed. Material is insured
and monitored against all
back in the original containers, in the same order they
were in before treatment.
loss or damage while it is on
our premises as well as in
transit back to the library or
archive.
... and the archive of
unpublished
Libraries and archives in the United States, Canada,
Europe and Asia trust the effectiveness an(
incredible value of the Bookkeeper process.
Years of independent testing and
research establish the reliability of
the Bookkeeper process.
Preserving the Value
Strict quality control measures are used to ensure effective treatment
of Cultural Property
Libraries and archives in
the United States, Canada,
Europe and Asia trust the
effectiveness and incredible
value of the Bookkeeper
process.
For pennies a page, and
with minimal preselection,
hundreds of thousands of
volumes and millions of
pages of manuscripts and
documents have already
been deacidified at one of
Preservation Technologies'
facilities.
papers and documents.
Barbara Tuchman
8
Preservation Technologies provides products and services to
preserve paper and books for libraries and archives
worldwide. Its breakthrough preservation processes and
products were developed to meet the standards of the
United States Library of Congress for safe and effective acid
neutralization and preservation of paper. Preservation
Technologies' patented processes also meet current and
projected OSHA, FTC and EPA consumer and environmental
requirements.