The Office of Environmental Health Hazard Assessment (OEHHA) has posted comments received on its July 29, 2011, revised proposed regulation concerning the specification of hazard traits, environmental and toxicological endpoints, and other relevant data that are to be included in California’s Toxics Information Clearinghouse.  The California Department of Toxic Substances Control (DTSC) will use information from the Clearinghouse to help identify chemicals of concern in consumer products as part of its Green Chemistry Program. OEHHA’s August 2010 pre-regulatory draft regulation included a “nanomaterial hazard trait,” as well as other references to nanoparticles, which OEHHA removed from its December 17, 2010, draft regulation. The revised regulation does not refer to nanomaterials or nanoparticles, but includes the following definition regarding particle size or fiber dimension:

(a)        The particle size or fiber dimension hazard trait is defined as the existence of a chemical substance in the form of small particles or fibers or the propensity to form into such small-sized particles or fibers with use or environmental release.

(b)        Evidence for the particle size or fiber dimension hazard trait includes, but is not limited to:  measures of particle size less than or equal to 10 micrometers in mass median aerodynamic diameter for inhalation exposure, or less than 10 micrometers in any dimension for dermal or ingestion exposure, or fibers with a 3:1 aspect ratio and a width less than or equal to 3 micrometers.