US NIOSH reports on explosivity of carbonaceous nanomaterials

A recent post by the National Institute for Occupational Safety and Health (NIOSH) details work over the last decade by scientists at the NIOSH Nanotechnology Research Center (NTRC) studying the explosion hazard of nanocarbons, nanocellulose, and nanometals to fill data gaps on the explosivity of nanomaterials. Scientists studied the dispersibility (the tendency of dust to disperse and remain airborne), explosion severity, and explosion sensitivity (measured through the minimum ignition energy [MIE] and minimum explosive concentration [MEC]), of a suite of nanomaterials.

The researchers found that the screened carbonaceous nanomaterials (including single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene and more) were ‘weakly explosive’ (European Dust Explosion Class St-1), similar to wood dust. The explosion severity of these materials did not depend on their primary particle size. Nanocrystalline and nanofibrillated cellulose were found to be ‘strongly explosive’ (European Dust Explosion Class St-2) and some of the screened nanometals were found to be ‘very strongly explosive’ (European Dust Explosion Class St-3).

Overall, the research at the NIOSH NTRC suggests that the nanomaterials investigated behaved similarly to their bulk material counterparts. However, NIOSH NTRC recommends continued research and caution especially as new and more advanced nanomaterials are developed and used in commerce.