Carbon Nanotubes Risks.pdf

The National Institute for Occupational Safety and Health (NIOSH) has issued a Current Intelligence Bulletin (CIB) to address the potential health risks associated with occupational exposure to carbon nanotubes (CNTs) and nanofibers (CNFs).
CNTs and CNFs are tiny, cylindrical, large aspect ratio, manufactured forms of carbon that may pose a respiratory hazard.
Animal studies have shown adverse lung effects, including pulmonary inflammation and fibrosis, at relatively low-mass doses of CNT and CNF.
NIOSH proposes a recommended exposure limit (REL) of 1 µg/m3 elemental carbon as a respirable mass 8-hour time-weighted average (TWA) concentration to minimize worker exposure.
Strategies for controlling workplace exposures and implementing a medical surveillance program are also described.
Preliminary findings from a new laboratory study suggest that multi-walled carbon nanotubes (MWCNT) may increase the risk of cancer in mice exposed to a known carcinogen.
NIOSH urges employers to share this information with workers and customers and requests that professional and trade associations and labor organizations inform their members about the potential hazards of CNT and CNF.

Key Recommendations

Minimize worker exposure to CNTs and CNFs.
Implement a recommended exposure limit (REL) of 1 µg/m3 elemental carbon as a respirable mass 8-hour time-weighted average (TWA) concentration.
Control workplace exposures through engineering controls, personal protective equipment, and medical surveillance.
* Continue research to better understand the hazards associated with CNTs and CNFs and to develop more effective strategies for controlling workplace exposures.