Nanotechnology and its Impact on the SH

1
Nanotechnology and its Impact on the SHE
Profession

• Presented by Robert C. Adams, MS, CIH, CSP
• ENVIRON International Corporation
• Princeton NJ

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Overview

• Nanotechnology a primer
• Applications for nanomaterials
• Types of engineered nanomaterials
• Managing Uncertainty The concern for
  nanoparticles
• Toxicological studies
• Health issues
• Safety issues
• Environmental issues
• Engineering, PPE and administrative controls
• Current thinking on traditional control methods
• Moving forward with SHE management what to do
  now

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Nanotechnology

• Terminology
• Nano - A prefix meaning one billionth
  (1/1,000,000,000)
• Nanotechnology
• Research and development of materials at the
  atomic, molecular or macromolecular levels,
• Approximately 1 - 100 nanometer range.
• Embraces a wide range of applications and
  products
• Little agreement on the terminology
• Nanomaterial any material that contains a
  certain proportion, or is composed entirely of,
  nanoparticles

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Nanotechnology

• Terminology (cont)
• Nanoparticle - nanometer-scale particles that are
  initially produced as aerosols or colloidal
  suspensions
• Nanotubes
• single-wall carbon nanotube
• multi-wall carbon nanotubes

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Nanotechnology

• Terminology (cont)
• Nanowires
• Small conducting or semi-conducting nanoparticles
  with a single crystal structure and a typical
  diameter of a few 10s of nanometers and a large
  aspect ratio.
• Quantum Dots
• Nanoparticles made up of hundreds to thousands of
  atoms that behave like a single gigantic atom.

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Source Office of Basic Energy Sciences, Office
of Science, U.S. Department of Energy
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Materials used as light-emitting diodes with the
color determined by the size of the quantum
dots Source Phillips
Carbon Nanotubes Source BBC News July 29, 2004
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Model of a C-60 Buckminster Fullerene (Buckyball)
Silver nanowire 50nm thick, 100nm wide and 5µm
long Source Quantronics
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Nanotechnology

• Purposely engineered materials and devices that
  demonstrate new, unique and non-scalable
  properties and behavior due to their size and
  configuration
• Will use nanoparticle in all further discussions

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Why Nanoparticles?

• Nanoparticles follow classical laws of physics
• Follow quantum physics
• Can assume different physical, optical,
  electrical or magnetic properties
• Nanoparticles have greater ratio of surface area
  to mass
• Greater reactivity with other substances

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Applications for Nanoparticles

• Nanotechnology is in the pre-competitive stage
  but
• Nanoparticles are here now!
• Bumpers on cars
• Paints and coatings
• Stain-free clothing and mattresses
• Burn and wound dressings
• Ink
• Protective and glare-reducing coatings for
  eyeglasses and windshields
• Metal-cutting tools
• Sunscreens and cosmetics
• Longer-lasting tennis balls and light-weight,
  stronger tennis racquets

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Managing Uncertainty

• What do we know about these nanoparticles?
• What dont we know?
• Does the nature of nanoparticles present new
  safety and health risks?
• What are the potential risks and what is the
  magnitude?
• We know very little about health effects (though
  many are laying the foundation)

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Managing Uncertainty

• What are (or could be) the
• Occupational health effects
• Safety hazards and
• Environmental impacts?

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Managing Uncertainty

• What can be expected concerning regulating
  nanotechnology risks?
• There are no laws in the US currently regulating
  nanotechnology
• What additional pressures will drive SHE efforts
• Insurance
• Investors
• Litigation
• Moral and ethical obligations to the workforce
  and community

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Managing Uncertainty

• What prudent steps are needed to manage the
  uncertainty?
• Currently, SHE programs are in the early stages
  of development
• Now is the time to define needs

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Managing Uncertainty

• Bottom Line
• Can we achieve the promises of nanotechnology
  while minimizing potential risks?

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Workplace Issues

• Current workforce mixed
• RD operations
• Technology-based
• Large numbers of small facilities and labs
• Universities and small enterprises

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Workplace Issues
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Workplace Issues

• Explosive growth projected in commercialization
  of nanotechnology
• Hundreds of thousands of new and redefined jobs
• Increasing shift toward piloting and ramping-up
  production operations
• Full-scale production is projected to take years

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Workplace Issues

• Employees in all areas will have potential for
  exposure
• Workforce is on the front line
• Appropriate controls available?
• Methods to measure exposure?

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Toxicological Issues

• Properties of nanoparticles that will influence
  toxicity
• Particle size
• Key factor in where particles deposit in the lung
• May influence ability of nanoparticles to
  translocation to other organs
• Composition/Structure
• Presence of heavy metals (nickel, beryllium,
  aluminum, etc.)
• Carbon nanotubes may exert different effects than
  carbon nanoparticles

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Toxicological Issues

• Properties of nanoparticles that will influence
  toxicity (cont)
• Solubility
• Soluble particles can dissolve in moist tissues
• Insoluble particles may be cleared from the lungs
  or may translocate to other organs
• Surface area/structure
• Smaller particles greater surface area
• More chemical reactivity
• More sites for cell/protein interaction
• Oxidative stress?toxicity, DNA damage, tumors

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Toxicological Issues

• Scientific basis of toxicology, epidemiology
  (exposure assessment and risk evaluation) lagging
  behind
• Inherently slower
• Long-term effects subject to long latency periods
• Production could outpace protections
• Not all materials will be problematic

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Toxicological Risks

• Potential for increased absorption?
• Increased absorption and penetration of
  biological barriers
• Ability to reach deep airways
• Systemic distribution
• Penetrate blood-brain barrier
• Potential for new toxicities from engineered
  nanomaterials?

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Toxicity Research

• Relatively few studies on engineered
  nanomaterials
• In vitro, isolated cells or tissues
• Short-term animal studies, mostly rodents
• Direct introduction to the lungs
• Studies on related materials
• Metal fume
• Ultrafine particulates (esp. beryllium)
• Mineral fibers

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Toxicity Research
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Limitations of Current Data

• No studies greater than 3 months duration
• No dose-response data
• No developmental/reproductive studies
• No chronic bioassays
• Not possible to set health protective limits
  without assumptions about toxicity relative to
  that of the same macro-scale material

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Industrial Hygiene Issues

• Exposure Metrics
• Exposure Monitoring
• Ventilation Control
• Personal Protective Equipment
• Respiratory Protection

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Exposure Metrics

• Nanoparticles may not be suitable for comparison
  to traditional exposure metrics
• Mass based metrics may understate exposures
• Particle number and/or surface area metrics may
  be a more reliable indicator of exposure

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Exposure Metrics

• Some consideration of particle size fractions may
  be relevant
• Number of particles less than 100 nm 50 nm 10
  nm
• One type metric may not be suitable for all

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Exposure Metrics

• Current research related to beryllium exposure
  and prevalence of disease indicates traditional
  metrics (mass per unit volume) may not be
  protective
• Alternative metrics based on particle size,
  particle number, or particle surface area may be
  more indicative of risk

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Exposure Monitoring

• If traditional exposure metrics are not
  applicable, traditional monitoring methods will
  not be viable to assess exposure
• What Do You Measure?

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Exposure Monitoring

• There are limited air sampling methods
• Real time particle counters / particle sizers
• Cascade impactors in the nanoparticle range
• High resolution TEM

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Three stage nanoparticle cascade impactor capable
of proving three particle size fractions - 32,
18 and 10 nm. Source MSP Corporation
Condensation particle counter capable of
measuring particles to 10 nm. Source TSI
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Exposure Monitoring

• Traditional filter/gravimetric methods cannot be
  used
• 1 µm particle weighs 1,000,000 times more than a
  10 nm particle
• Larger particles mask the weight of nanoparticles
• Mass concentration must be inferred from measured
  size distribution number concentration

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Exposure Monitoring

• An ideal sampler would be able to measure
  particle surface area and particle number within
  several size fractions
• Such a sampler is not currently available
• Most likely monitoring will require using
  combinations of instruments
• Costs are significant

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Exposure Monitoring

• Personal sampling techniques not readily
  available
• Current research on cutting edge beryllium
  sampling methods may lead to methods that may
  have application to nanoparticles
• Additional study is needed to more fully
  characterize and validate the sampling
  methodologies

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Considerations for Control

• Nanoparticle behavior will influence control
  approaches
• Behave more like gases
• migrate from areas of highest concentration
• May agglomerate
• Gravitational settling much slower than other
  particle types
• May widely disperse
• Re-suspension may be a concern

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Considerations for Control

• Ultrafine particles in mixtures have been a
  concern for SHE professionals
• Diesel exhaust fumes
• Welding fumes
• Carbon black
• Dust created in the destruction of the WTC
  (including asbestos and silica)

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Considerations for Control

• Applications of exhaust ventilation
• Nanoparticles may present the following
  challenges
• Effectiveness of filtration
• Design of hoods and enclosures
• Capture and transport velocities
• Current thinking is that conventional local
  exhaust ventilation approaches should work
• Design must consider both gaseous and particulate
  behavior

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Considerations for Control

• Design and installation of ventilation systems
  based on controlling gas and particulate will
  provide prudent first steps for worker protection
• E.g. fine wood dust particulates, welding fumes
  and vapors from stationary sources
• Application of design principals based on ACGIH
  Ventilation Manual

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Considerations for Control

• Use of respiratory protection
• Nanoparticles may present the following
  challenges
• Filtration of ultrafine particulates
• Criticality of facial seal for negative pressure
  respirators
• Effectiveness of positive pressure respirators
• Appropriateness of fit factors or protection
  factors

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Considerations for Control

• Current thinking is that modern respiratory
  protection technology is sufficient, but more
  research is needed
• New filter media? New materials of construction?
• Fit testing methods may require further
  improvements

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Considerations for Control

• PPE
• Nanoparticles may present the following
  challenges
• Small sized particles may easily penetrate
  traditional knit clothing
• Ocular exposure a concern?
• Modern PPE materials of construction will likely
  provide protection from all but the smallest
  materials
• Ocular protection may present some additional
  challenges

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Considerations for Control

• SHE professionals will be challenged to
• evaluate dermal exposure pathways
• utilize published guidance in selection of PPE
  ensembles
• develop implementation schemes
• assess effectiveness of implementation

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Safety Issues

• Fire / Explosion Hazards
• Composition of nanoparticles
• Increased surface area more easily ignited?
• Nanoparticles may persist for longer in the air
• Risk could be either greater or smaller

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Environmental Issues

• Increased concern about releases beyond immediate
  application / manufacturing site
• Consider potential releases via
• Take-home exposures
• Transport
• Manufacturing waste streams
• Product waste streams

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Environmental Issues

• Available pathways to air, soil or water
• Little is known about the fate of nanoparticles
  in the environment
• Will such materials be assimilated
• How mobile and persistent
• What breakdown products may be produced due to
  environmental transformation/degradation

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Model for Action
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Scientific Base

• Scientific foundation must be built in parallel
  to prudent workplace measures
• Societal obligation to generate and publish
  scientific findings
• Necessary to support policy formulation

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Regulatory Framework

• A realistic regulatory framework will ultimately
  be needed
• NIOSH is currently in the forefront on workforce
  matters
• NIOSH is pursuing strategic, multidisciplinary
  research that will help practitioners, with
  greater certainty, to apply the well-established
  principles of occupational safety and health to
  workplace exposures involving nanomaterials.
• NIOSH is evaluating the unique benefits that
  nanotechnology may bring to improving
  occupational safety and health.

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Regulatory Framework

• OSHA is only in the formative stages of gathering
  information
• Standards that would currently be applicable
• Hazard communication 1910.1200
• Occupational exposure to hazardous chemicals in
  laboratories. - 1910.1450
• Respiratory protection 1910.134
• Personal protective equipment 1910.132

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Regulatory Framework

• EPA
• TSCA is one of the statutes under which
  commercial applications will likely be regulated
• Key question - Is a nanoparticle of a chemical
  which is intended to impart new chemical and/or
  physical properties, to be considered
• a new chemical
• a significant new use of an existing chemical
• a modified but not significant new use of an
  existing chemical or
• none of the above?

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Regulatory Framework

• Most likely, TSCA will apply at some level
• EPA probably will not treat nanoparticles as new
  chemical substances
• EPA probably will treat each new category of
  nanoparticles as a significant new use

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Practical Approaches

• Identify individuals that may be at risk
• Identify others who are at little to no risk, for
  comparison
• Work in conjunction with other professionals
  (toxicologists and epidemiologists)

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Practical Approaches

• Prioritization of issues
• Identifying pragmatic approaches
• Classifying substances
• Performance-based controls
• Adaptations of existing successful approaches
• Potent compounds model (pharma, biotech,
  microbiological)

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Practical Approaches

• Not all substances of equal concern
• Unclear which are priority materials
• Understanding is evolving
• Ability to be proactive vs. reactive
• Exposure reduction, control

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Practical approaches

• Engineering control of exposure
• PPE and employee training
• Exposure monitoring
• Health surveillance
• Willing to adjust or pull the plug if necessary

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Conclusions

• Limited available science should not deter
  development of effective safeguards
• Build on existing models
• Err conservatively
• Multidisciplinary approaches will be needed

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Conclusions

• Objective communication of both risks and safety
  critical in an environment susceptible to
  sensationalism
• Substantiated through science and practice
• Not limited to scientific community
• Nanotechnology will challenge conventional
  approaches to addressing occupational safety and
  health risk

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Thank You

• badams_at_environcorp.com
• 609.243.9848