On October 12, 2011, the Office of Administrative Law approved an amendment to Title 27, California Code of Regulations, sections 25703(a)(6). The amendment modifies the calculation used to convert estimates of animal cancer potency to estimates of human cancer potency, which is used to calculate no significant risk levels for carcinogens listed under Proposition 65. The amendment changes the existing regulatory provision to a ratio of human to animal bodyweight to the one-fourth power for interspecies conversion and deletes the provision giving specific scaling factors for mice and rat data. The amendment is effective on November 11, 2011. The amended regulatory text and the supporting rulemaking documents are available at the following links:
Questions regarding this regulatory action can be directed to Monet Vela, at monet.vela@oehha.ca.gov or (916) 323-2517 or Carol J. Monahan-Cummings, Chief Counsel at carol.mcummings@oehha.ca.gov or (916) 322-0493.
