Presented at the 2011 ACS National Fall Meeting in Denver, Colordao

1. Exposure Monitoring
Techniques for Nanomaterials
American Chemical
Society Meeting
August 30, 2011
Joseph M. Pickel, Ph.D. CHO
Center for Nanophase Materials Sciences
Oak Ridge National Laboratory
UT-Battelle
Department of Energy

2. Acknowledgements
 Scott Hollenbeck, CIH (ORNL-CNMS)
 John Jankovich, CIH (ORNL- Ret)
 Burt Ogle, Ph.D., CIH (Western Carolina)
 Tracy Zontek, Ph.D., CIH (Western Carolina)
 Randy Ogle, CIH (ORNL-Ret, RJLee Group)
 Gary Casuccio (RJLee Group)
 Michaela Hall, MPH (ORNL)
 Samantha Connell (Alabama, Birmingham)
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3. Outline
 Challenge and General Strategy for
Nanomaterial Safety in the Laboratory
 Review of Current Approaches
 Discussion of New Developments
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Department of Energy

4. Challenge
 Ensure that we are protecting workers
– From materials that vary in size, shape, and
composition
– Having unknown toxicity and reactivity
– By measuring a number of properties (count, surface
area, mass)
– Using tools, sometimes at or near their limits of
quantitation
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5. Nanoscale Materials Properties
 Relatively little mass
– Mass of 1 billion 10 nm particles = mass of 10 µm particle
 Large surface area
 Produced in large numbers
 Quantum effects
– Change their physical, chemical, and biological properties
 Behave like gases
– Stay suspended for weeks
 Disperse quickly
 Tend to agglomerate quickly after production
– Good for health effects
– Bad for science
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6. Control of Nanoparticles
As in any hazardous exposure to
chemicals, a good health and
safety management approach
should include these four Identify the hazard Asses the risk
elements:
1.Identify the hazard
2.Asses the risk
3.Prevent or control the
risk
Evaluate the effectiveness Prevent or control the risk
4.Evaluate the
effectiveness of control
measures
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7. Starting Point: Identify/ Assess Situation
Lack of and/or uncertainty of data warrants that
Nanomaterials must handled using the precautionary
principle:
“toxic in the short run and chronically toxic in the long run”
Photos courtesy RJ LEE Group
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8. Prevent/Control Risk - Assumptions
- Traditional Controls Work
- Engineering
- Administrative
- Personal Protection
- Material Releases Can be Measured
- Hazard and associated Risk are product of
Toxicity and Exposure
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9. Evaluate Effectiveness of Controls
Sampling and Exposure Monitoring
 To check for releases
(process control)
– Leak checks on
containment
– Effectiveness of
capturing system
 To define ambient
concentration
– Establish need for
exposure control
 Exceedance of regulated
concentration
 Exceedance of operational
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guidelines
Department of Energy

10. Challenge
 Ensure that we are protecting workers
– From materials that vary in size, shape, and
composition (what are we looking for?)
– Having unknown toxicity and reactivity (how much is
okay?)
– By measuring a number of properties (count, surface
area, mass) (which is most important)
– Using tools, sometimes at or near their limits of
quantitation (how many tools are enough?)
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11. Current Guidance on Nanomaterial Safety
 NIOSH: Approaches to Safe Nanotechnology
 DOE Nanoscience Research Centers: Approach to Nanomaterial
ES&H (Rev 3a, 5/08)
 ISO/TR 12885:2008, Health and safety practices in occupational
settings relevant to nanotechnologies
 ASTM E2535 - 07 Standard Guide for Handling Unbound Engineered
Nanoscale Particles in Occupational Settings

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12. Foundation of NSRC Approach…
 Integrated Safety
Management followed
from inception
 Designed to
accommodate the
planned R&D
 ESH and projected R&D
staff designed individual
labs and controls
 Used experience,
benchmarking, and best
available control
technologies
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13. Nanotechnology Safety Approach
 Sound Workplace Practice – SOGs/SOPs
 Effective workplace controls: engineering,
administrative, and PPE where appropriate (i.e. protect
routes of entry, particularly inhalation and dermal
exposures).
 Safety and Health Training – disseminating appropriate
hazard information
 Safe procedures for handling and disposal of
hazardous (and potentially hazardous) materials.
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14. Controls to limit exposure
Install similar engineering controls
used to control gases and vapors:
Enclosures
Local exhaust ventilation
Fume hoods
Use of HEPA Filtration
Limitation on number of workers and
exclusion of others
Use of suitable personal protective
equipment
Good Chemical Hygiene (Prohibition of
eating and drinking in contaminated
areas, Regular cleaning of walls and
other surfaces)
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15. Tools for Evaluating Nanomaterial
Exposures
 Surface area – diffusion charger
 Scanning Mobility Particle Sizer (SMPS)
 Count– CPC(TSI), scanning mobility, GRIMM
 Composition/Chemistry - GC-MS
 Filter/Impinger/Impactor-TEM/SEM
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16. Sampling Strategy
 Determine if nanomaterials are controlled at the
source
– Use of Condensation Particle Counter, TSI 3007
 Range from 0.01 - >1 um with a concentration range of 0 to
100,000 particles/cc
– SMPS (Sequential Mobility Particle Sizer)
 Combination of electrostatic classifier and condensation particle
counter
 Determines particle sizes and distributions
– GRIMM Aerosol Spectrometer
 Particle sizes in 13 channels ranging from greater than 0.3 um
to greater than 10 um, with a count range from 1 to 2 million
counts per liter
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17. Sampling Approach for CNMS
Activities
 TSI 3007 CPC, particle counts to 10nm
 Nucleopore filter + SEM/TEM
– size,
– shape,
– metallic composition
 Baseline index of “clean” watch for other sources
(air pollution, combustion)
 Direct count, estimated mass, and surface area for
each process
 Passive monitoring (TEM/SEM Stub or grid)
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18. Working in fume hood
Activity / Materials Range (p/cc) Mean (p/cc) SD Time (s)
Room background 970-1344 1214.19 50.58 426
Grinding in hood 1161-1929 1580.73 164.38 540
Hood background 1481-1887 1665.16 78.83 145
At 10:09 a.m. to end of
log, baseline of inside
Grinding the barium the hood.
fluoride inside the
hood.
Crushed powder was shook
from the filter paper into a
glass holder.
CPC monitoring begins in
room F263.
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Department of Energy

19. Berkeley Study
 Worker and Environmental Assessment of
Potential Unbound Engineered Nanoparticle
Releases
– Multiphase study (Assessment and Control Band
Development)
– Conducted by LBNL and RJLEE group
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20. Evaluation of Spray System at CNMS
 Protocol used to survey efficacy of control
methods
 Results motivated change to administrative
protocols
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21. General Results of Sampling Protocol
 CPC
– Extremely effective to identify background levels and spikes
– Background levels crucial to data interpretation
– Not effective to collect employee exposure samples
 GRIMM Aerosol Spectrometer
– Provides particle size distribution
– Did not measure particles less than 300 nm
 Particle spikes found due to equipment:
– HEPA vacuum
– Heat exchanger on laser enclosure
 Controls and work practices were effective overall:
– Work in hoods (HEPA)
– Wet methods
– Closed systems / enclosures
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22. Discussion of Protocol
- Focus on research / laboratory environments (non-
production)
- Emphasis on CPC and Microscopy as convenient, universally
accessible tools
- Combination approach allows confirmation of source
- Protocol measures particle count, distribution and
composition
- Forgo gravimetric measurements due to technical concerns
- Forthcoming revision of protocol removes GRIMM
- Continuous Improvements to method via research
– on new equipment and components
– Sampling methods and assumptions
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23. Exposure limits for Nanomaterials
 No current regulatory limits
 ALARA in R&D (Prudent Practice)
 Current guidance (and tox data) based on
mass (e.g., LD50 mg/Kg)
 Older standards based on particle counts
 Not yet a foundation for a surface area based
dose-response
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24. Other Considerations –
Emerging Toxicity Information
 Depends on chemistry,
morphology, surface charges,
etc.
 Probably relates to particle
surface area especially for
insoluble/low soluble
 Free radicals (in vitro)
 Increased inflammatory
response (in vivo)
 Translocation to target organs
(rodents)
 Allergic asthma like symptoms
 Aggravate symptoms of
pneumonia
 Cardiac effect-2 days later
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25. NIOSH on Titanium Dioxide
 Exposure limit of 1.5 milligrams per cubic meter for
fine TiO2 (particles greater than 0.1 micrometers in
diameter)
 0.1 mg/m3 for ultrafine particles as time-weighted
averages for up to 10 hours per day during a 40-hour
work week
 Suggests that ultrafine TiO2 particles may be more
potent than fine TiO2 particles at the same mass.
This may be due to the fact that the ultrafine
particles have a greater surface area than the fine
particles at the same mass
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Department of Energy

26. Surface area as dominant characteristic
contributing to toxicity is plausible
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27. Nanoparticle Surface Area is Huge!
8
1
• 1/2 the size = 2x
the surface area
and 23 = 8x the
number or
particles
• Approaches 100%
of atoms on the
surface
64 512
•www.gly.uga.edu/railsback/1121WeatheringArea.jpeg
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28. Discussion on Exposure Guidelines
 Current progress is towards mass based
limits
– NIOSH proposes mass based Recommended
Exposure Limit
 Basis approximates limits of quantitation
rather than toxicological considerations
 Forthcoming article to propose 530 p/cc
(53000p/cc for respirator) for non-doped
carbon based aerosols
– Extrapolated particle based guideline
– Applicable to poorly soluble, low toxicity
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29. Summary and Conclusions
 All processes should be carefully evaluated and
prudent controls in place prior to start
– Control banding
 Air monitoring can evaluate release of nanoscale
materials in workplace
– Determine effectiveness of controls
 Poor work practices can lead to potential
contamination
 Follow standard IH practices focusing on evaluation
and control
 Consider end results and future
– Characterize materials
– Ensure health and safety
– Data for epidemiological studies
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30. Summary and Conclusions
 Worker Health can be Asbestos Fiber
protected
– Prudent practices
– ALARA/ALARP Principles
– Control Banding
 Emerging information is
Welding Fumes
solidifying technical basis for
exposure assessment
– Toxicological data
– OELS
– Sampling methodology,
techniques and tools…
– But there is no “right answer” yet
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31. References and Resources
 Jankovic, J T; Hollenbeck, S M; “Ambient Air Sampling During Quantum-dot Spray
Deposition” International Journal of Occupational and Environmental Health 2010 ,16:4,
388-398.
 Jankovic, J.T; Ogle, B.R.; Zontek, T.L.; Hollenbeck, S.M. “Characterizing Aerosolized
Particulate As Part Of A Nanoprocess Exposure Assessment” International Journal of
Occupational and Environmental Health 16:4, 451-457
 Jankovic, J.T; Ogle, B.R.; Zontek, T.L.; Hall, M. A.; Hollenbeck, S.M. “Particle Loss in a
Scanning Mobility Particle Analyzer Sampling Extension Tube” International Journal of
Occupational and Environmental Health; 16:4, 429-433.
 Zontek, T. L. ; Ogle, B.R.; Ogle, R.B “Evaluating an air monitoring technique” Professional
Safety 2010 34 www.asse.org
 Nanotechnology research resources
– National Institute for Occupational Safety and Health (NIOSH)
– National Nanotechnology Initiative (NNI)
– Rice University's International Council on Nanotechnology
(ICON)
– Nanoparticle Information Library (NIL)
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