The National Institute for Occupational Safety and Health (NIOSH) accepted public comment until February 18, 2011 on its draft document entitled "Current Intelligence Bulletin: Occupational Exposure to Carbon Nanotubes and Nanofibers." A copy of the bulletin can be found at http://www.cdc.gov/niosh/updates/upd-12-02-10.html. Nanomaterial is extremely small. For example, a nanometer is one billionth of a meter. Nanomaterial is used in a variety of uses, including industrial and medical applications.
NIOSH notes the following in its bulletin:
- Studies argue that the long and thin structure of some carbon nanotubes and carbon nanofibers dimensionally resemble asbestos fibers;
- Studies argue that multiwalled carbon nanotubes have been observed to migrate to the pleural tissue that is the same site in which malignant mesothelioma can develop due to asbestos exposure;
- Animal studies have shown asbestos-type pathology associated with exposure to longer, straighter carbon nanotube structures; and
- The recommended exposure limit of elemental carbon is 7 micrograms per cubic meter of air for an 8 hour time weighted average.
NIOSH advises that ?the draft document summarizes current scientific knowledge about the occupational safety and health implications of carbon nanotubes and carbon nanofibers, and recommends an occupational exposure limit and measures for controlling work-related exposures to those types of nanomaterials?? NIOSH also advises that additional research is needed for workers in the manufacture and industrial use of carbon nanotubes and carbon nanofibers.
In all likelihood, NIOSH will recommend that the Occupational Safety and Health Administration (OSHA) implement permissible exposure limits or recommended exposure limits that could apply to employees? workplace exposure to carbon nanomaterial.