The CDC's National Institute for Occupational Safety and Health is particularly concerned about the use of two nanomaterials: carbon nanotubes and carbon nanofibers, which are used in numerous industrial and biochemical applications. NIOSH has drafted recommendations to limit exposure until more is known about the technology.
What it is.
According to NIOSH, "nanotechnology involves the manipulation of matter at nanometer length (one-billionth of a meter) scales to produce new materials, structures and devices." The materials produced are not new. The red and yellow hues in stained glass "result from the presence of nanometer-diameter gold and silver particles." What is fairly new is the ability to probe, manipulate, understand, and engineer matter at atomic scales.
An increasing number of products and materials make use of nanotechnology. For example, nanoscale titanium dioxide "is finding uses in cosmetics, sun block creams, and self-cleaning windows, and nanoscale silica is being used as a filler in a range of products, including dental fillings," according to NIOSH. Also, the technology is being used to improve consumer products "such as stain and wrinkle-free fabrics incorporating 'nanowhiskers' and longer-lasting tennis balls using butyl-rubber/nanoclay composites." Nanocoatings and nanocomposites are being used in "a wide variety of consumer products from bicycles to automobiles."
NIOSH is recommending limiting occupational contact and other measures to control work-related exposures until more is known about the materials. With the growth of public awareness and the use of nanotechnology, stakeholders agree that "prudent stewardship of nanotechnology is essential for public acceptance and U.S. competitiveness in the global market," said NIOSH Director Dr. John Howard.
The draft recommendations include:
- Minimized work-related exposures until scientific studies can better determine the potential health effects of exposure to carbon nanotubes and carbon nanofibers. Specifically, it recommends a "strategic approach for assessing potential work-related exposures and risks, controlling exposures through a hierarchy of measures, instituting appropriate medical screening programs, and educating workers on sources and job tasks that may expose them to these types of nanomaterials."
- A recommended exposure limit of 7 micrograms of each material per cubic meter of air as an eight-hour, time-weighted average, respirable mass concentration -- the concentration that can be most reliably measured with current instrumentation. While admitting that the recommended exposure limit might not be completely health protective, the draft document says it "should help lower the risk of developing work-related lung disease and assist employers in establishing an occupational health surveillance program that includes elements of hazard and medical surveillance."
- Reduced airborne concentrations "as low as possible below the REL by making optimal use of sampling and analysis."
NIOSH is seeking public comment on the document through Feb. 18. The agency is holding a public meeting on the document in Cincinnati on Feb. 3.
Read more at the WorkersComp Forum homepage.
January 17, 2011
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