California Agency Changes Animal Cancer Conversion Calculation
The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) has issued a notice addressing its amendment to “the calculation used to convert estimates of animal cancer potencyto estimates of human cancer potency, which is used to calculate no significant risk levels for carcinogens listed under Proposition 65.”
According to the notice, the amendment took effect November 11, 2011, and
will change “the existing regulatory provision to a ratio of human to animal
bodyweight to the one-fourth power for interspecies conversion and delete[]
the provision giving specific scaling factors for mice and rat data.”
OEHHA has also announced that its Carcinogen Identification Committee has been asked to consider whether Dibenzanthracenes should be added to the Proposition 65 list. These substances are ubiquitous polyaromatic hydrocarbons that are the product of incomplete combustion, and human exposure may occur from contaminated food or water. Public comments are requested by January 10, 2012.
In other action, OEHHA has posted “the comments of three external peer
reviewers of the draft public health goal for perchlorate that was released
for public comment in January 2011.” The comments were submitted by
researchers from the Oregon Health & Science University, University of North
Texas Health Sciences Center and University of Rochester School of Medicine
and Dentistry. Perchlorate exposure in the United States mostly occurs from
ingestion of contaminated food or water. The chemical is used in a variety of
chemical processes.
