A Proposal for the Regulation of Occupational Exposure to Nanomaterials

A PROPOSAL FOR THE REGULATION OF OCCUPATIONAL EXPOSURE TO NANOMATERIALS  Tee L. Guidotti, MD, MPH, DABT. Medical Advisory Services, Rockville MD, USA. tee.guidotti/at/gmail.com  There is a need for a consistent regulatory approach to nanomaterials but no clear studies to date that characterize the risks under operating conditions. Ultrafine particulate air pollution could provide a “peg” by which to anchor a regulatory regime. The Canadian Council of Ministers of the Environment has adopted a Canada-wide standard (CWS) for PM2.5 (fine particulate matter at or below 2500 nm) of 30 mcg/m3 24-hour average, as the 98th percentile of the range permitted over any three year period, which took effect in 2010. This benchmark represents a convenient upper bound for an “almost” worst case scenario if applied to particulate nanomaterials, appropriate for a hazard for which no threshold applies. A benchmark occupational exposure level (not an occupational exposure limit, or OEL) of 30 mcg/m3 8-hour time-weighted average would be applied to nanoparticles that are believed to be relatively inert, at least until such time as their safety could be evaluated. Those with features likely to confer more biological activity would be subject to uncertainty or safety factors, possibly using the traditional factor of 0.1. The resulting modified exposure level would become the provisional standard for a specific product until sufficient data became available for a proper risk assessment.  This low level of allowable exposure would undoubtedly drive control technology toward containment for many or most processes and in that sense is precautionary but would give the industry a firm basis for planning and a “level playing field”.  For details of this proposal, please see: Guidotti TL. The regulation of occupational exposure to nanomaterials: a proposal. [Editorial] Arch Environ Occup Health 2010;65(2):57 – 58.