Manufactured and Engineered
Nanoparticles-TiO2:
What can be learned from SCENIHR, … and others
Thomas Jung
SCENIHR
Scientific Committee on Emerging and Newly Identified Health Risks
Manufactured and Engineered Nanoparticles-TiO2:
1
SCENIHR Mandate
Scientific Commitee for New and Emerging Health Risks
Emerging or newly identified risks, broad, complex or
multi-disciplinary issues requiring a comprehensive
assessment of risks to consumer safety or public health
Risk management issues are specifically excluded
Examples
physical hazards (e.g. noise and electromagnetic fields)
new technologies (e.g. nanotechnologies)
medical devices, blood products
biological hazards (eg antimicrobial resistance)
methodologies
for assessing
risks
Manufactured
and Engineeredemerging
Nanoparticles-TiO2:
3
SCENIHR – mode of working
Question(s) framed by one or more Commission Services.
Question discussed in the SCENIHR. Chairman of the Working
Group (WG) is appointed.
External experts are identified and invited to the WG. (NB all
members must declare any relevant interests at each meeting).
WG identifies methodology to be used.
Progress reports given at each SCENIHR meeting.
WG produces a draft report.
Report is discussed at SCENIHR and a preliminary report / final
opinion is agreed.
Manufactured and Engineered Nanoparticles-TiO2:
4
Methodology
Key issues in the evaluation
For each paper selected both the methods used
and the findings are assessed.
Good studies with positive or negative findings
are given equal weighting.
Publications, not supported by data that can be
assessed by the WG, are not considered.
Manufactured and Engineered Nanoparticles-TiO2:
6
Nano
SCENIHR procedure
Nano: Where and What?
SCENIHR Nano Opinions
Discussion of TiO2 issues raised by
Colipa and BEUC
Manufactured and Engineered Nanoparticles-TiO2:
9
Nanoparticles – Scientific Background
Surface and Interface Science I. Langmuir ~20’s @ GE,
~70’s
Colloid Science
e.g. ‘Nano-Gold’, Nano-colloids, Liposomes,…
‘Aerosol’ Science ~80’s
Aerosol generation / Combustion Aerosols
Characterisation in gas suspension
Cluster Chemistry / Physics ~80’s
Solid State Physics / Size Effects ~60’s
 Difficulty related to definition only by feature size
across so many (and more) disciplines
Note: nanoparticles in ceramics / dyes ~900 AD
Optical properties of nm scale metals
M. Faraday, Phil. Trans. Roy. Soc. London 147 p145 (1857)
Manufactured and Engineered Nanoparticles-TiO2:
10
Why nanomaterials: Controlling properties
size / dimensionality dependence of physical
properties
------
Cu < 50 nm “super-hard”
~ nm metal “conductivity”
~ 100 nm “optical absorption”
~ 10 nm “ magnetism”
…
miscibility / tunability of compound properties
 metamaterial
Note: Almost any physical property depends on
particle size
Manufactured and Engineered Nanoparticles-TiO2:
12
Definitions matter -- but
‘Nano’ < 100 nm ??, micro, milli, meter
0.1
atoms
1m
1
10 100 1u 10u 100u 1mm 1cm 1m
bacteria
hair
foil
finger
109 m ~1M km
~ distance to the moon 
‘defining’ the border between the planet and space,…
 Suggests legislative compromise
Manufactured and Engineered Nanoparticles-TiO2:
13
Nanoparticles – what’s new then?
‘manufactured and engineered’ – for certain
applications
some new issues in risk assessment
‘standing on the shoulders of giants’
 rapid evolution of the field
Manufactured and Engineered Nanoparticles-TiO2:
15
Nanomaterials: Parameters of Interest
Physical properties
• Size, shape, specific surface area, aspect ratio
• Agglomeration/aggregation state
• Size distribution
• Surface morphology/topography
• Structure, including crystallinity and defect structure
• Solubility
Chemical properties
• Structural formula/molecular structure
• Composition of nanomaterial (including degree of purity, known
impurities or
additives)
• Phase identity
• Surface chemistry (composition, charge, tension, reactive sites,
physical
structure, photocatalytic properties, zeta potential)
• Hydrophilicity/lipophilicity
Manufactured and Engineered Nanoparticles-TiO2:
17
Why is the Surface so Critical?
Surface & Interface Science
25 nm
5 nm
Manufactured and Engineered Nanoparticles-TiO2:
18
‘details’ matter
totally dirty or totally clean
‘practical manufacturing’  minority
contamination  surface coating
critical dependence of overall behaviour on
surface layer
if not stabilized: time evolution of particle size
distribution ( larger d)
kinetic, dynamic Effects need to be anticipated
Manufactured and Engineered Nanoparticles-TiO2:
19
Changes of nano-material in medium
SCENIHR(2009)
Manufactured
and Engineered
Nanoparticles-TiO2:
 Potentially affecting
fate
/ distrib.
24
Nanoparticle toxicity: Issues
persistence depending on agglomeration, disagglomeration,
and on degradation,
relevance of routes of exposure to individual circumstances,
metrics (e.g. mass or surface) used for exposure
measurements,
mechanisms of translocation to different parts of the body
and the possibility of degradation after nanoparticles enter
the body,
mechanisms of toxicity,
phenomenon of transfer between various environmental
media.
Not new: Chemical reactivity, Degradation (~ surface area! )
SCENIHR ‘TGD’ 2007
Manufactured and Engineered Nanoparticles-TiO2:
26
Predominant Concern
‘free’ nanoparticles
insoluble or ‘low solubility’ nanoparticles
airborne nanoparticles
in view of scientific progress:
limited reference materials
SCENIHR 2006
Manufactured and Engineered Nanoparticles-TiO2:
30
Exposure Assessment Algorithm
SCENIHR ‘TGD’ 2007
Manufactured and Engineered Nanoparticles-TiO2:
32
Nanoparticle-Toxicity
SCENIHR ‘TGD’ 2007
‘nano’ target organs possibly beyond portal of entry
 secondary target organs
interspecies differences ? ?? extrapolation to human
effect assessment
effect assessment usually requires in vivo studies for
dose-responserelationships at target organs
understanding modes of actions and underlying
mechanisms
Manufactured and Engineered Nanoparticles-TiO2:
34
Staged approach
(SCENIHR TGD 2007)
Stage 1: Identify whether manufacture, use and/or end
of use disposal/recycling could result in exposure of
humans and/or environmental species.
Stage 2: Characterise the nature, level and duration of
any exposure
Stage 3: Identify the hazardous properties of any forms
of the nanomaterial to which significant exposure is likely
Stage 4: Characterisation of hazard and final risk
assessment
Manufactured and Engineered Nanoparticles-TiO2:
36
Precautionary Matrix
(Swiss Federal Offices of Public Health / Environment)
Topics:
Nano-Relevance
Life Cycle
Potential Effect
Physical Surroundings
Exposure of human beings
Input into the Environment
Questions:
Physiological conditions: Agglomeration /
Deagglomeration
Physiological conditions: Stability of material / coating
Environment: Stability
Manufactured and Engineered Nanoparticles-TiO2:
41
Take Home Messages:
Nanomaterials
Definitions for regulatory purposes needed.
Acceleration by sectorial approach?
SCENIHR defined Science based procedure towards
nanoparticle risk assessment
Use of available information on materials
TiO2 serves as a first case: Current evaluation by
Scientific Committee of Consumer Safety (SCCS) and
SCENIHR
Suggested comparison with alternative approaches (CHmatrix)
Manufactured and Engineered Nanoparticles-TiO2:
42
Colipa issues:
Long Term, High Volume use:
 Chemistry / Surface Chemistry somewhat
established
but:
Metric and size dependency of established
endpoints
Toxicokinetics modified by (Size, Metric)
here: Transport and accumulation
-- in the ‘relevant’ form, agreed
Manufactured and Engineered Nanoparticles-TiO2:
44
Colipa issues (II):
Soluble cosmetic ‘nano’ ingredients
 not first priority by SCENIHR
but chemical substance
compare nano & non-nano toxicokinetics
 agrees with SCENIR
OECD tests O.K for est. endpoints  new
effects need new approaches
Labelling: -- not a SCENIHR topic
Manufactured and Engineered Nanoparticles-TiO2:
45
BEUC issues: Nano-Accounting
NANOTECHNOLOGY: AN OVERVIEW BASED ON INDICATORS AND
STATISTICS, OECD STI WORKING PAPER 2009/7
Christopher Palmberg, Hélène Dernis and Claire Miguet
“Hockey Stick” of Nanotech ~invention of STM (1981) (p13)
Public Investment rocketing (p30)
"R&D investment data on nanotechnology are incomplete due to the
lack of commonly agreed definitions and statistical frameworks, while
publication and patent data only can provide a limited picture of the
variegated nature of technological change and innovation.“ (page 4)
Patent portfolio cited therein contains ‘technologies’ established pre‘81.
What is Nano and what is Not? Nano ‘on’ is not Nano ‘in’
Manufactured and Engineered Nanoparticles-TiO2:
48
BEUC issues (II):
topic here: TiO2
Emulsions  Check Components at first prio
Fullerenes are molecules
N.B. recognised by the House of Lords
Nano-metals – important issue
Calcium peroxide – to be discussed
Manufactured and Engineered Nanoparticles-TiO2:
49
BEUC issues (III):
Risk and Benefit: UV absorbers (TiO2 vs. organic)
Contradicting discussions: Yes, that is what science is all
about: Factual controversies, research …
Accumulation / Eco-accumulation is covered
Penetration / Aggregation / Accumulation
 ‘one Form’ agreement with Colipa
Recommendations: Not an issue of SCENIHR
Manufactured and Engineered Nanoparticles-TiO2:
50
This paper was produced for a meeting organized by Health & Consumers DG and represents the views of its author on the
subject. These views have not been adopted or in any way approved by the Commission and should not be relied upon as a statement of
the Commission's or Health & Consumers DG's views. The European Commission does not guarantee the accuracy of the data
included in this paper, nor does it accept responsibility for any use made thereof.