Accident Prevention Manual

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• Accident Prevention Manual
• for Business Industry
• Engineering Technology
• 13th edition
• National Safety Council

Compiled by Dr. S.D. Allen Iske, Associate
Professor University of Central Missouri
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CHAPTER 14

• NANOPARTICLES

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Nanotechnology

• Collection of technologies dealing with materials
  science on the nanometer scale.
• Special concerns
• inhalation hazard for humans
• free unbound nanoparticle and nanofiber materials
• absorption routes into the body (skin, lungs,
  blood, brain, and other target organs)
• comprehensive hazard assessment

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Historical Perspective

• Nanoparticles are not a new phenomenon.
• Scientists were aware of colloids and sols, for
  more than 100 years. The scientific investigation
  of colloids and their properties was reported by
  Faraday (1857) in his experiments with gold. He
  used the term divided metals to describe the
  material which he produced.
• Zsigmondy (1905) described the formation of a red
  gold sol which is now understood to comprise
  particles in the 10 nm size range.

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Definitions/Sizes

• Nanotechnology involves the creation and/or
  manipulation of materials at the nanometer (nm)
  scale either by scaling up from single groups of
  atoms or by refining or reducing bulk materials.
• A nanometer is 1 x 10-9 m or one millionth of a
  millimeter. A human hair is 10,000 to 50,000 nm,
  a single red blood cell has a diameter of around
  5000 nm, viruses typically have a maximum
  dimension of 10 to 100 nm and a DNA molecule has
  a diameter of 212 nm (www.nano.gov).

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Nanomaterials

• Ordinary materials such as carbon or silicon,
  when reduced to the nanoscale, often exhibit
  novel and unpredictable characteristics
• extraordinary strength, chemical reactivity,
  electrical conductivity, or other characteristics
  that the same material does not possess at the
  micro or macro-scale
• A huge range of materials have already been
  produced including nanotubes, nanowires,
  fullerene derivatives (bucky balls), and other
  nanoscale materials.

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Categories and Applications

• Nanostructure
• Nanotubes
• Nanowires
• Nanocrystals
• Other nanoparticles

• Example Material or Application
• carbon, (fullerenes)
• metals, semiconductors, oxides, sulfides,
  nitrides quantum dots insulators, semiconductors,
  metals, magnetic materials
• ceramic oxides, metals

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Current Status

• Limited current knowledge
• Industrial applications growing rapidly
• Professional and regulatory agencies interest and
  methods of assessment increasing
• Workplace hazards versus atmospheric emissions
  for exposure

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Knowledge Gaps

• The nanoparticle nomenclature is not sufficiently
  well described.
• There are no convenient methods by which
  exposures to nanoparticles in the workplace can
  be measured or assessed.
• There is insufficient knowledge concerning
  nanoparticle exposure.
• The effectiveness of control approaches has not
  been evaluated.
• Knowledge concerning nanoparticle risks is
  inadequate for risk assessments.

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Use at Worksite

• Occupational exposure control prior to
  introduction
• Examine toxicity and dose data

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Nanomaterials in Workplace

• Investigate and determine physical and chemical
  properties per potential toxicity
• Evaluate short and long-term effects on organ
  systems
• Determine biological mechanisms for toxic effects
• Create and integrate models in assessing possible
  hazards
• Determine if mass or other property informs
  toxicity impact

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Measurement Methods

• Important for accuracy and protective measures
• Evaluate methods of measuring respirable
  particles in the air and application to
  nanomaterials
• Develop and field test practical methods to
  measure airborne nanomaterials
• Develop testing and evaluation systems to compare
  and validate sampling instruments

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Preparing Workplace

• Exposure assessment - worksite and workers for
  exposure potentials
• Machine and plant floor
• Cleaning crews
• Finished product testing
• Packaging
• Spray applications
• Particle size and absorption properties

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Risk assessment

• Potential exposure to nanomaterials
• Determine current exposure-response data (human
  or animal) to identify and assess potential
  occupational hazards
• Develop framework for evaluating and predicting
  potential occupational risk to exposure of
  nanomaterials

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Monitoring Results

• Epidemiology and surveillancemeasurements of
  consequences of nanomaterials use
• Evaluate existing workplace studies with
  nanomaterials.
• Identify knowledge gaps of understanding of
  nanomaterials and conduct new studies.
• Integrate health and safety issues in existing
  surveillance methods and additional screening
  methods.
• Use existing systems data and information.

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Engineering Controls and PPE

• Employers legal duty and practical obligation to
  utilize protectionspreventing harm to workers
• Control methods
• Ventilation systems, clean rooms, glove box,
  respiratory protection, face shields,
  clothingminimize air and skin exposures to
  nanomaterials to prevent harmful effects

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Protection Controls Research

• Evaluate effectiveness of engineering controls in
  reducing occupational exposuresnanoparticles or
  nanoaerosols.
• Evaluate and improve PPE.
• Develop recommendations to prevent or limit
  exposures (e.g., respirator fit testing).
• Evaluate control banding techniques, information
  gaps, and effectiveness of alternate. methods

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Explosion and Fire Risks

• Identify physical and chemical properties that
  contribute to dustiness, combustibility,
  flammability, and conductivity of nanomaterials.
• Recommend alternative work practices to eliminate
  or reduce workplace exposures.
• Develop a disposal protocol reducing potential
  for harm to workers in waste-handling systems.

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Regulatory Issues

• Agencies to evaluate current regulatory
  requirements for nanomaterials for worker
  protection from exposures
• National Institute for Occupational Safety and
  Health (NIOSH)
• Occupational Safety and Health Administration
  (OSHA)
• U.S. Environmental Protection Agency (EPA)