From OEHHA:
Notice of Proposed Rulemaking Title 27, California Code of Regulations Amendment to Section 25805 Specific Regulatory Levels: Chemicals Causing Reproductive Toxicity Sulfur Dioxide (SO2).
NOTICE IS HEREBY GIVEN that the Office of Environmental Health Hazard Assessment (OEHHA) proposes to establish a Proposition 65 Maximum Allowable Dose Level (MADL) for sulfur dioxide (SO2) of 220 micrograms per day by amending Section 25805(b) of Title 27 of the California Code of Regulations.
To download the reasonings for the potential listing or to submit comments see the above link.