Notice of Proposed Rulemaking Title 27, California Code of Regulations Amendment to Section 25805 Specific Regulatory Levels: Chemicals Causing Reproductive Toxicity Sulphur Dioxide (SO2)

On 28 June 2012 California’s Office of Environmental Health Hazard Assessment (OEHHA) announced a proposal to establish a Proposition 65 Maximum Allowable Dose Level (MADL) for sulphur dioxide (SO2) of 220 micrograms per day by amending Section 25805(b) of Title 27 of the California Code of Regulations. Proposition 65 prohibits a person in the course of doing business from knowingly and intentionally exposing any individual to a chemical that has been listed as known to the State to cause cancer or reproductive toxicity, without first giving clear and reasonable warning to such individual. The Act also prohibits a business from knowingly discharging a listed chemical into water or onto or into land where such chemical passes or probably will pass into any source of drinking water. OEHHA reviewed relevant studies on the developmental toxicity of sulphur dioxide, which were identified through comprehensive searches of the scientific literature. For purposes of Proposition 65, the study by Murray et al., in mice is the most sensitive study deemed to be of sufficient quality as defined in Section 25803(a)(7) for exposure to sulphur dioxide. OEHHA relied on the values from this study as the basis for calculating the MADL for sulphur dioxide proposed for adoption into Section 25805(b). By providing a MADL, this regulatory proposal spares businesses the expense of calculating their own MADL and may also enable them to reduce or avoid litigation costs. In addition, the MADL does not require, but may encourage, businesses to lower the amount of the listed chemical in their product to a level that does not cause a significant exposure, thereby providing a public health benefit to Californians. The agency has requested that comments concerning this proposed action, be submitted by 20 August 2012. All comments received will be posted on the OEHHA website at the close of the public comment period. Further information is available at:

California’s OEHHA, 28 June 2012 ; ;