Nanotechnology Safety
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Nanotechnology is “the Next Big Thing.” It
is a truly international phenomenon that
“will have a major impact on the health,
wealth and security of the world’s people
that will be at least as significant in this
century as antibiotics, the integrated
circuit, and manmade polymers.”
National Science and Technology Council Committee on Technology, 1999
Top Ten Ways that Nanotechnology Will Impact
Our Lives in the Next 10 years
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Diagnosing Diseases
Treatment of Cancer and Other Diseases
Widespread Adoption of Solar Energy
New Batteries and Other Forms of Portable Power
Blending Electronic and Paper-Based Products
Lighter, Stronger, and More Conductive Materials
Clean Water
Low Emission Automobiles
Responding to Terrorism and Environmental Disaster
Increased Monitoring of Consumer Products
– There are currently 807 nano products in the Consumer Products Inventory
Source : NANOTECHNOLOGY LAW & BUSINESS - FALL 2007 (editors)
Nanotechnology Products Are Here Now
Dermatone
SPF 20
Natural
Formula
Socks with
Nano Silver
Eddie Bauer
Ruston Fit
Nano-Tex
Khakis
Nanotec
Nanoseal®
Nanosolar’s
Utility Panel™
Wood
Kodak Inkjet
Photo Papers
Kohler CleanCoat
Technology
Toshiba’s LithiumIon Battery
Hummer
H2
Tata’s Nano
PURPOSE
• For the present, there is minimum regulatory control for
nanoparticles (NP). This suggests that for the short-term
industry must self-regulate itself (take the lead in evaluating
and managing risks).
• Localized “standards of care” or safety approaches will need
to be promulgated that protect health and environmental
risks when working with nanoparticles (NP).
• This presentation gives draft SHE “standards of care” for
working with NP.
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KEEP IN MIND...
• Current understanding of the environmental and
human health effects of NP is limited.
• Ultimately, information about definite health effects
will emerge. Until then-it will be prudent to adopt
conservative approaches for managing and
controlling perceived NP risks.
• Unfortunately, the commercialization of
nanomaterials is growing so fast that it is difficult to
study NP impact on human and environmental
health issues. {i.e. Recent reports in Europe over
“Magic Nano” spray}
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DEFINITIONS
• Nanotechnology: simplest definition is technological
developments on the nanometer (nm) scale. Nano is
a prefix meaning one billionth; 1 nm = 10-9 m
• Nanoparticle (NP): any substance less than 100 nm.
(A single human red blood cell has a diameter about
5000 nm)
• Nanomaterial: any material that contains a certain
proportion, or is composed entirely of, nanoparticles.
Could be nanotubes, nanowires, quantum dots.
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HOW BIG IS A NANOMETER?
• A nanometers is equal to one billionth of a meter or
10-9 m
• A flea is 10-3 m or 1 mm
• A human hair is 10-4 m or 80 um
• A red blood cell is 10-5 m or 7 um
• A strand of DNA is 10-8 m or 2 nm
• A bundle of nanotubes is 1.4 nm wide
• A carbon 60 fullerene is 0.7 nm
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THERE IS A CRUCIAL NEED TO
STANDARDIZE TERMINOLOGY AND
DEFINITIONS, DEVELOP METHODS
TO MEASURE NP, AND IMPROVE
CONTROL MEASURES THAT LIMIT
OCCUPATIONAL EXPOSURE!
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Silver nanowire 50 nm thick, 100 nm wide
and 5 um long. (Quantronics)
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Some Nanotechnology Applications
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Energy storage, production, and conversion
Agricultural productivity enhancement
Water treatment and remediation
Disease diagnosis and screening (Bio- and Nano-)
Drug delivery system
Food processing and storage
Air pollution and remediation
Construction
Health monitoring
Vector/Pest control
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GENERAL BACKGROUND
• NP applications will definitely expand with time.
• NP enhances coating surface properties.
• NP can be purchased or manufactured either bound
or unbound.
• Many small particles create a large amount of
surface area, which tends to become electrically
charged, leading to chemically reactive conditions.
• NP <50 nm have properties that do not follow
classical physics laws-do follow quantum physics
laws.
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Particle Number and surface area for
area for 10 mg/m3 airborne particles
Particle
Diameter (um)
2.0
0.5
0.02
Particles/ml
of air
2
153
2,390,000
Particle Surface
area (um2/ml of air)
30
120
3000
Large particle
Small particle
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GENERAL BACKGROUND
• Safety Concerns-Small size particles (<<0.1
um) may have higher human risks than the
range from 0.1 to 30 um. We know very little
about most of them compared to the same
substances with larger particle sizes.
• It is difficult to characterize worker exposure
to particles that have a diameter less than the
wavelength of light. Therefore SHE risk
assessment technique may not directly apply!
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POTENTIAL EXPOSURE RISKS
1.
2.
3.
4.
5.
Airborne contamination of workplace
Handling of product/material
Cleaning/Maintenance activities
Leakage/Spillage Accidents
Product Drying
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Risks?
Nanotechnology – Recent Developments, Risks and
Opportunities
Lloyd’s of London, November 2007
– Clean-up costs of land and water contamination
– Medical costs of treatment of human exposure
– Liability claims from persons directly affected, environmental
groups and shareholders
– Unexpected life, health and workers compensation
– Latent liability claims of persons affected
– Business interruption while facility is investigated
– Cost of product recall
Inhalation Exposure Studies
with NM
Mercer -NIOSH
• Nanoparticles not captured by respiratory
defense systems
• Nanoparticles can enter lung tissues and
be distributed to other organs and tissues SWCNT
• Inhaled nanoparticles may pass from the
nose to brain through the olfactory nerve collagen
• Rigid multiwalled carbon nanotubes longer
than 20 µm elicit the same toxic response
elastin
in mice that asbestos does, according to
two new studies
TII
Endothelia
Fibroblast
capillary
Dermal Exposure Studies with NM
• Reports of penetration of intact skin
in test system models by:
– Multi-walled carbon nanotubes
– Substituted fullerenes
– Quantum dots
• In vitro tests indicate inflammatory
and cytotoxic responses after
exposures to nanomaterials
Human Health Concerns for NM
• NM exposure and toxicity not yet well
understood
• Nanoscale materials do not behave like
their bulk counterparts
• Increased reactivity of NM due to large
surface area
• Potential for bioaccumulation and
accumulation in food chain
Carbon nanotubes
Environmental Concerns for NM
• Water/soil contamination from
improper disposal?
• Disposition and fate after product use
and disposal?
• Degradation products?
• Potential for accumulation in food
chain?
Limited environmental testing data available
Occupational Concerns for NM
• Extent and impact of worker exposures to NM
• Effectiveness of personal protective equipment to
minimize/eliminate NM exposures
• Difficulties in monitoring workplace exposures
– Small size of NM
– Limited protocols and methodologies
• Fire and explosion hazards
• Catalytic potential of NM
Maynard 2004
KEY TOXICOLOGICAL FACTORS
Physical Related
Chemical Related
• Composition and
Structure
• Solubility
• Reactivity
• Surface Chemistry
• Aggregation Potential
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Surface Area
Shape
Density
Particle Size
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TOXICOLOGICAL ISSUES
• NP may be more toxic than larger particles on a
mass basis (high surface area to mass ratio). The
smaller the particles the more reactive and toxic
they become. Deeper into lung.
• Not all materials will represent risks
• Potential for new toxicities from engineered
nanomaterials?
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TOXICOLOGICAL ISSUES
• The major routes of entry of NP into the body
are:
1. Lungs (Inhalation)-Considered to be a big
concern.
2. Gastrointestinal tract (Ingestion)
3. Dermal (Absorption)-Little information
about dermal exposure from NP. SPE data is
not readily available. Large exposure site!
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TOXICITY STAGING
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Route of Exposure
Dose
Duration of Exposure
Movement in Body
Interaction within Body
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HUMAN HEALTH EFFECTS
• Examples of possible health issues that have been
reported in animal studies are oxidative stress,
inhalation/transdermal assimilation concerns,
asthma, chronic pulmonary diseases, cancer,
neurodegenerative diseases, alteration of heart
electrical activity, translocation (i.e. crossing of
blood-brain barrier), and cell signaling. Strong
evidence that pulmonary inflammation is related to
surface area.
• At present there are no national occupational
exposure standards? In fact few human research
studies have been performed to date
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POSSIBLE REGULATORY ACTIVITY
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OSHA: HAZCOMM (MSDS)
EPA: RCRA, TSCA, Clean Water/Air
FDA: Cosmetic Act
NIOSH: Active in TiO2
STATES
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NIOSH ACTIVITY
• Presently involved w/drafting exposure criteria for Titanium
Dioxide
• Material is used widely
• Animal studies (rat) show pulmonary inflammation, trauma,
tissue damage, and lung tumors. Appears to be particle size
dependent.
• REL of 1.5 mg/m3 for particles 0.1 to 10 um (fine) and REL of
0.1 mg/m3 for particles < 0.1 um (ultrafine)
• NOTE: Elevated lung cancer rates have been reported among workers
exposed to welding fumes and diesel particulates.
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HUMAN HEALTH EFFECTS
• It is now postulated that human health effects
are more closely related to total surface area
of particle than their mass-needs verification!
• At small particle sizes-atoms and molecules
bond differently than when in bulk
substances.
• Models that address particle deposition in the
lung exist.
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ICRP Lung Model
15 nm
3 nm
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RECENT BIO-EFFECTS OF NP
• Water soluble carbon nanotubes fed intravenously
to mice were excreted intact in urine and were not
retained in spleen, heart, and liver. This finding gives
some evidence that nanotubes might be used for
medical therapeutics purposes. Reported in Proc
Natl Acad Sci-USA-2006)
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IF WORKING WITH UNBOUNDED NP
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Total enclosure of process with negative ventilation or
partial enclosure with localized exhaust ventilation
(LEV). Install indicators to show air flow/present of
ventilation. Use dedicated exhaust system (May want
double enclosure). Particle entrainment is safety
feature.
Treat NP as if they were a gas (high to low
concentrations). Particles may undergo rapid mixing
and dispersion. As NP collide
coagulation/agglomeration occurs and NP can be
collected in bulk form-and probably not undergo resuspension.
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IF WORKING WITH UNBOUNDED NP
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Beware that small particles have low settling
velocity and remain airborne longer (minimal
inertia). Being airborne they can be trapped on
wall, ceiling, floor surfaces, and people far removed
from origination point.
Cover skin. Double up on gloves. Consider wearing
protective long-sleeved coats (i.e. layering
approach). Protective coats will need to be cleaned
on a regular basis.
No eating/drinking in work area.
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Count
No burner on
6000
T=2, Burner On, Notice counts &
Distribution delta
6000000
CountBi-modal distributionT=0,
Count
6000000
Count
5000000
5000000
4000000
4000000
T=7, Burner On, Counts &
Distribution the same as T=2
(minus the 10-20 nm feedstock)
5000
4000
3000000
Series2
3000000
3000
2000000
2000000
2000
1000000
1000
1000000
0
0
Particle size (nm)
Particle size (nm)
Count
1600000
1400000
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7
32
8
24
6
18
4
13
8
78
10
4
58
44
33
25
T=30, Burner Off & Room beginning to “Normalize”
(a.k.a. getting back to background bi-modal
distribution). Notice that the particulate counts are
down drastically also … supporting the “Wait for 5minutes before you enter the chamber Rule”
3000
T=20, Burner Off, Counts high
initially for small particles-large
particles not being made.
Distribution is similar to that for
T=0
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Particle size (nm)
Count
1800000
14
10
437
328
246
184
138
78
104
58
44
33
25
18
14
10
407
328
264
213
172
138
90
111
72
58
47
38
31
25
20
16
13
10
0
2500
2000
1200000
1000000
1500
800000
1000
600000
400000
500
328
36
264
213
172
138
Particle size (nm)
111
90
72
58
47
38
31
25
20
16
13
407
328
264
213
172
138
111
90
72
58
47
38
25
20
16
13
10
31
Particle size (nm)
10
0
0
407
200000
IF WORKING WITH UNBOUNDED NP
• HEPA filters/scrubbers (also N100) can be useful for
particles less than 100 nm (efficiency increases as
particle size decreases). Not sure about their use at 210 nm. Need to be aware of facial seal leakage
potential.
• Will be difficult to clean and maintain laboratory
equipment (as well as walls/floors) containing
nanoparticles without exposing workers (use of wet
methods)
• It is not clear that existing knowledge about
conventional chemicals can be applied predict risks of
nanomaterials.
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IF WORKING WITH UNBOUNDED NP
• Limit the number of workers per room
involved with NP. Reduce actual exposure
time.
• Potential for dust explosions/fires:
composition, increased surface area, NP in air
longer…
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IF WORKING WITH UNBOUNDED NP
• Electrostatic air filters may be use to collect NP since
charged particles have higher deposition efficiency
than uncharged particles. Some work being done
with soft x-rays and charged particles to further
enhance collection
• NP may act synergistically with O2 and NOx
• Laser Generated Air Contaminants (LGAC) could be a
source of NP.
• Some basic medical surveillance for lung
capacity/skin issues may be necessary.
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IF WORKING WITH UNBOUNDED NP
• At present, MSDS does not reflect nanospecificity. Not
sure if OSHA defines NP as falling under Hazard
Communication.
• “Bio-accumulation” of particles can occur in plants,
crops, water, and ground. Problems w/waste disposal
(options: encapsulation or incineration).
• May need to consider life-cycle testing on products.
Avoid future liabilities
• In view of the above concepts perhaps it is best not to
work with unbounded NP!
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CONTROL OF WORKPLACE
EXPOSURES TO NP.
Engineering Controls
Training and Good
Work Practices
Personal Protective
Equipment
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