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California Withdraws Proposal to Lower NSRL for Ethylene Oxide Under Prop 65


The California Office of Environmental Health Hazard Assessment (OEHHA) has withdrawn the proposed rulemaking to update the No Significant Risk Level (NSRL) for ethylene oxide. In April 2023, OEHHA had proposed lowering the "No Significant Risk Level" (NSRL) from ethylene oxide from 2 to 0.058 micrograms (µg) per day for the inhalation route and 1.5 µg/day via the oral route under the state’s Safe Drinking Water and Toxic Enforcement Act of 1986 (also known as Proposition 65). The comment period on that proposal originally was scheduled to end on January 10, 2024, but was extended to January 17, 2024. (More information on the proposal to lower the NSRL for ethylene oxide can be found here.)

In the announcement about withdrawing the proposal, OEHHA stated that it intends to restart the rulemaking process at a later time. In the meantime, the existing NSRL of 2 µg/day for ethylene oxide remains in effect.