As you may recall, the Office of Environmental Health Hazard Assessment (OEHHA) added sulfur dioxide as a chemical known to cause reproductive toxicity to the Proposition 65 list of chemicals on June 29, 2011.  Today, the OEHHA issued two important notices regarding sulfur dioxide. 

First, OEHHA issued a Notice indicating that it proposes to establish a Proposition 65 Maximum Allowable Dose Level (MADL) for sulfur dioxide of 220 micrograms per day.  This would be accomplished by amending Section 25805(b) of Title 27 of the California Code of Regulations.  Any written comments concerning this Notice must be provided to OEHHA by August 6, 2012.  OEHHA will hold a public proceeding regarding this Notice on August 20, 2012.  The documents concerning this Notice, including the relevant analytical information, are available at

Second, OEHHA issued an Interpretive Guideline regarding sulfur dioxide in dried fruits.  OEHHA concluded that a Proposition 65 warning is not required for dried fruits because the exposure to sulfur dioxide through the consumption of dried fruits is lower than the proposed MADL for sulfur dioxide.  Accordingly, companies that sell dried fruit products in California do not need to warn consumers about the presence of sulfur dioxide in their products for purposes of Prop 65.  The complete Guideline is available at:

Many of us in the Prop 65 industry have been anticipating action by OEHHA on sulfur dioxide, since the listing of the chemical (without limiting it to an inhalant) has been controversial.  Notably, the Initial Statement of Reasons from OEHHA regarding the proposed MADL noted that the MADL was based on inhalation data and that “OEHHA concluded that exposure to [sulfur dioxide] by the oral route is expected to pose no more risk, and may pose less risk, than exposure to the equivalent amount by the inhalation route.”  The proposed MADL and the Interpretative Guideline should enable companies to better assess whether they need to warn under Prop 65 regarding the existence of sulfur dioxide in their products.