NIOSH issues recommended exposure limit for carbon nanomaterials

Washington – NIOSH on April 24 issued a recommended worker exposure limit of 1 microgram per cubic meter of air for carbon nanotubes and carbon nanofibers.

As explained in a new Current Intelligence Bulletin (.pdf file), NIOSH’s recommendation is based on laboratory studies, published research and observations of industrial processes.

Workers are at risk of inhaling loose CNTs and CNFs, which are man-made particles used in products such as plastics, paints and electronics. To reduce workplace exposure, NIOSH recommends:

• Use engineering controls to enclose processes in which CNTs or CNFs could become airborne, such as when dry, fine powders are transferred between containers.
• Train workers in safe handling of nanoparticles, engineering and administrative controls, and safe work practices.
• Establish health surveillance and medical screening programs to identify early signs of respiratory disease in workers.