The Federal Advisory Council on Occupational Safety and Health (FACOSH) met on May 3, 2012, during which it discussed the use of occupational exposure levels (OEL) by the federal government. Because the Occupational Safety and Health Administration’s (OSHA) permissible exposure limits (PEL) have remained unchanged since their adoption on May 29, 1971, and do not account for advances in technology or the latest data, FACOSH asked its Emerging Issues Subcommittee to analyze federal agencies’ use of PELs. As part of its review, the Subcommittee identified other issues of interest, including dispersible engineered nanomaterials (DENM). A document entitled “Recommendations for Consideration by the U.S. Secretary of Labor on the Adoption and Use of Occupational Exposure Limits by Federal Agencies” includes the following text concerning DENMs:
- OSHA defines nanomaterials as, “materials that have been purposefully manufactured, synthesized, or manipulated to have a size with at least one dimension in the range of approximately 1 to 100 nanometers and that exhibit unique properties determined by their size.”
- Published scientific studies have indicated that at least some DENMs are biologically active, have produced toxicological reactions in the lungs of exposed experimental animals, and may readily penetrate intact human skin. While DENMs are truly an emerging issue and published results are not plentiful, scientists and federal agencies, such as NIOSH, continue to conduct research to understand fully the potential health effects of exposure.
- Currently, both scientists and federal agencies agree that DENM toxicity depends heavily on the physical and chemical properties of the nanoparticles, such as particle size and size distribution, agglomeration state, shape, crystal structure, chemical composition, surface area, surface chemistry, surface charge, and porosity, and that these properties may differ substantially from those of the same material in macro-scale form.