The California Office of Environmental Health Hazard Assessment (OEHHA) has released for comment a pre-regulatory draft regulation regarding the specification of hazard traits, environmental and toxicological end-points, and other relevant data that are to be included in California’s Toxics Information Clearinghouse. The California Department of Toxic Substances Control (CDTSC) will use information from the Clearinghouse to help identify chemicals of concern in consumer products as part of its Green Chemistry Program.

The draft regulation defines “exposure potential hazard traits” to include “particle size or fiber dimension,” including the existence of a chemical substance in the form of nanoparticles or fibers. The draft regulation states that a chemical substance has this hazard trait if it is in particle form in the nanoparticle size range (less than or equal to 0.1 micrometers in mass median aerodynamic diameter). Under the draft regulation, physical hazard traits, which may affect human health or the environment, include:

Nanomaterial hazard trait

  1. The nanomaterial hazard trait is defined as hazards due to a chemical substance having greater toxicity when in nanoparticle form than in bulk form.
  2. Nanoparticles or nanosized fibers, that are particles that are 100 nm or less in any dimension, or would be defined as nanoparticles . . ., may have this trait.

An informal comment period on the pre-regulatory draft regulation ends on September 13, 2010.