Manufactured Nanomaterials

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Manufactured Nanomaterials

• Dendrimers
• Nanoclays
• Carbon black
• Fullerenes (C60)
• Single-walled carbon nanotubes (SWCNTs)
• Multi-walled carbon nanotubes (MWCNTs)

• Aluminum oxide
• Cerium oxide
• Iron nanoparticles
• Silver nanoparticles
• Titanium dioxide
• Zinc oxide
• Silicon dioxide
• Polystyrene

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Nanotechnology
Safety and Health Issues and Concerns Dennis J.
Cesarotti, PhD, CIH, CSP (deceased) Department of
Technology, Northern Illinois University Martin
Kocanda, MSEE, Ph.D. College of Engineering and
Engineering Technology
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Nanotechnology

• Manipulation of matter at a nanometers scale
  producing structures, materials, and devices.
• Particles 100 nanometer or less.
• Does size really make a difference relative to
  the safety and health of nano-particles?

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Objectives Safety and Health, Issues and Concerns
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TLO 1 How nanotechnology influences the hazards
of a chemical

• Enabling Objectives
• Define the hazards of chemicals.
• Identify potential hazards.
• Recall examples of specific nano-particles.

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TLO 2 What nanotechnology is in relation to
human physiology

• Enabling Objectives
• Recall function and structures of the human body.
• Contrast the size of nano-particles to the
  components of the human body.

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TLO 3 How can humans be exposed to
nanomaterials

• Enabling Objectives
• Describe the routes of entry into the human body.
• List common activities that could contribute to
  exposure.

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TLO 4 How nanoparticles may influence human
health

• Enabling Objectives
• Describe the potential health effects on the
  systems of the body.
• List the common symptoms and etiology associated
  with the health effects.

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TLO 5 What exposure control measures can be
used to minimize adverse health effects

• Enabling Objectives
• Discuss control options.
• Compare and contract the control methodology.
• Determine the effectiveness of control measures.

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TLO 6 What forms of medical surveillance can
be used to diagnose early adverse health effects

• Enabling Objectives
• Explain the importance of a detailed medical
  history.
• Discuss the role of exposure monitoring.
• List the medical surveillance techniques.

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TLO 1 How does nanotechnology influence the
hazards of a chemical?
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Hazards of a Chemical?

• Flammability
• Corrosivity
• Toxicity
• Reactivity

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Fire and Explosion risks

• This applies to metals and organic materials. The
  risk is likely to be highest if nanodusts are
  formed during the production process (e.g. if
  when spray drying a Suspension of nanoparticles,
  the solvent evaporates during the process and a
  nanoaerosol is created.

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Flammability

• Flashpoint
• The lowest temperature of a fuel where sufficient
  vapor is present to result in a fire or
  explosion if a source of ignition is present.
• Auto Ignition Temperature
• Lowest temperature where the chemical will
  breakdown and ignite.

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Flammability (continued)

• Explosive Limits
• LEL
• Lowest concentration of fuel in the air
  expressed as a percent.
• UEL
• Highest concentration of fuel in the air for
  combustion.
• Above UEL, fuel rich, will not burn.
• Flammable Range
• Difference between UEL and LEL

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Combustible Dusts (continued)

• Combustible dust size lt 40 um.
• Minimum explosive concentration (MEC).
• Decreasing the particle size increases the
  potential for and rate of combustion.

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Combustible Dusts (continued)

• Minimum ignition temperature.
• Minimum ignition energy (MIE).
• lt 3 mJ high sensitivitygt 10 mJ low
  sensitivity

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Explosivity Scale

• Class II test
• Ignition Sensitivity (IS) gt 0.2
• IS TIm EIm CEm (time, energy,
  concentration)
• Normalized to Pittsburgh coal (PC/D)
• Explosion Severity (ES) gt 0.5
• ES PEM RPRM (max pressure and max pressure
  rise)
• Normalized to Pittsburgh coal (D/PC)
• US Bureau of Mines developed the standard

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Combustible Dusts (continued)

• Kst Test
• Maximum normalized rate of pressure rise (dP/dt)
• Kst (dP/dt)M V1/3

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http//www.farrapc.com/articles/explosion-venting-
requirements/affected
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Combustible Dusts (continued)

• Flammable particles
• Carbon
• Metals
• Organic polymers

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Combustible Dusts (continued)

• Large surface / volume ratio.

Bulk materials do not easily ignite. Pile of
powder does not easily ignite. Dispersed powder
is very explosive. http//www.teachertube.com/vie
wVideo.php?titleDust_Explosionvideo_id155518 h
ttp//www.metacafe.com/watch/587885/simulate_a_dus
t_explosion/ http//www.ebaumsworld.com/video/wat
ch/80623061/
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Corrosivity

• pH measure of corrosivity
• Scale from 0 to 14
• Acids pH of 0 to 6.9
• Caustics or bases pH of 7.1 to 14
• pH 7 neutral

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Corrosivity (continued)

• Concerns
• Acids lt 2.0
• Bases gt 12.0
• Corrosive to tissue
• Acids sit on surface
• Can be washed off quickly
• Local damage
• Bases
• Can penetrate tissue

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Toxicity

• Paracelsus (1493 - 1541)
• All substances are poisons, there is none which
  is not a poison. The right dose differentiates a
  poison and a remedy.
• The dose makes the poison

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Toxicity (continued)

• Exposure Factors
• Concentration
• Duration
• Frequency
• Size
• Route of Entry
• Total body dose

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Toxicity (continued)
Dose Response Curve
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Toxicity (continued)
1s (67 )
Number of Responses
2s (95 )
Minimal
Mean
Extreme
Degree of Response
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Toxicity (continued)

• Typical Health Effects
• Irritation
• Corrosive
• Allergen
• Asphyxiant
• Systemic
• Carcinogenic
• Reproductive

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Toxicity (continued)

• Chemical exposures are generally divided into two
  categories
• Acute
• Chronic
• Symptoms of an acute exposure may be completely
  different from those resulting from chronic
  exposure

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Toxicity Acute Exposure

• Symptoms usually occur during or shortly after
  exposure to a sufficiently high concentration of
  a contaminant
• Concentration required to produce such effects
  varies widely from chemical to chemical

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Toxicity Chronic Exposure

• Generally refers to exposures to low
  concentrations of a contaminant over a long
  period of time
• The low concentrations required to produce
  symptoms of chronic exposure depend upon
• The chemical
• The duration of each exposure
• The number of exposures

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Reactivity

• Ability to reach with other molecules
• Chemical reaction
• Polymerization
• Decomposition
• Oxidation
• Reduction
• Release of
• Heat
• Pressure
• Other particles

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Reactivity (continued)

• Otherwise inert materials can be highly reactive
• Nanoparticles can generate heat through the
  progression of reactions

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Where can this safety information be found?
Material Safety Data Sheet (MSDS)
Review of MSDS Handout for Propane
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Homework Assignment Write two paragraph
explanation that compares Graphite powder and
silica dessicant powder. Address all of the key
safety issues. What make the materials
different? What is the common safety risk of
both? Perform a web search for the MSDS for each.