California OEHHA (Office of Environmental Health Hazard Assessment) is the lead government agency charged with implementing Proposition 65, CAâ€™s Safe Drinking Water and Toxic Enforcement Act of 1986. Prop 65 requires the publication of a list of chemicals â€śknown to the stateâ€ť to cause cancer or reproductive toxicity. Under Prop 65, â€śsignificant exposureâ€ť to any of the listed chemical substances resulting from a manufactured product requires that a warning label be placed on the product if it is sold in California. For some of the substances, Safe Harbor Levels have been developed defining significant exposures. In the absence of a Safe Harbor Level, a manufacturer whose product contains a listed substance is advised to perform a risk assessment to determine if there is potential for significant exposure.
New chemicals added to Cal Prop 65 list
The list of chemicals of concern for Prop 65 is under continuous development. The Developmental and Reproductive Toxicant Identification Committee of OEHHA has determined that there is sufficient evidence to list xylene isomers (technical xylene, CAS 1330-20-7; o-xylene, CAS 95-47-6; m-xylene, CAS 108-38-3; and p-xylene, CAS 106-42-3). OEHHA has just released (September 28, 2012) a review of literature on the developmental and reproductive toxicity of xylene. It reviews human epidemiologic studies and animal studies that address developmental toxicity and male and female reproductive toxicity. The release marks the beginning of a 60-day public comment period ending November 27, 2012. The review provides the committee with the information it will use to make a determination regarding the listing of xylene as a Prop 65 reproductive toxicant.
How does general public come in contact with xylenes?
Exposures of the general public to xylenes probably occur primarily from evaporative emissions of gasoline and from motor vehicle tailpipe emissions. In particular, attached garages have been shown to be a significant source of exposures in residences. Xylenes also are widely used as solvents in product manufacturing. Such products include various types of finishes and adhesives. If xylenes are listed, manufacturers will need to choose among conducting risk assessments since there is no safe harbor value, attaching warning labels to products sold in California, or switching to alternate solvents.
Other Prop 65 carcinogen listed in OEHHA
In other OEHHA news (Sep 14, 2012), the agency announced the proposed listing of alpha-methylstyrene, CAS 98-83-9, as a Prop 65 carcinogen. This action is occurring under the Labor Code Mechanism which requires the listing of substances identified as human or animal carcinogens by the International Agency for Research on Cancer (IARC).
And in more OEHHA Prop 65 news for September, the agency has posted a priority list for the development of safe harbor levels. Priority levels were assigned based on the availability and quality of scientific data on potential exposure and dose-response relationships and on expressed need. For first priority substances, No Significant Risk Levels (NSRLs) for carcinogens and Maximum Allowable Dose Levels (MADLs) for reproductive toxicants will be developed over the next two years. The first priority list contains some chemicals of interest to building product and furniture manufacturers. These include: 1,3-dichloro-2-propanol, diethanolamine, methyl isobutyl ketone, propylene glycol mono-t-butyl ether, butyl benzyl phthalate (BBP), 2-ethylhexanoic acid, methanol, and others.