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California Adds Methyl Isobutyl Ketone and Megestrol Acetate to List of Proposition 65 Chemicals

April 22, 2014

The Office of Environmental Health Hazard Assessment (OEHHA) added both methyl isobutyl ketone (MIBK) and megestrol acetate to the list of chemicals known to the state of California to cause reproductive toxicity for purposes of Proposition 65.

The listing of methyl isobutyl ketone is based on formal identification by the U.S. Environmental Protection Agency (EPA), an authoritative body, that the chemical causes reproductive toxicity (developmental endpoint).

The listing of megestrol acetate is based on a formal requirement by a state or federal agency that the chemical be identified or labeled as causing cancer as provided under the Act.