No Significant Risk Levels for Ethylene Oxide

Withdrawal of the Proposed Rulemaking to Update the NSRL for Ethylene Oxide

The Office of Environmental Health Hazard Assessment (OEHHA) decided to withdraw the proposed rulemaking intended to update the No Significant Risk Level (NSRL) for Ethylene Oxide.

OEHHA intends to restart the rulemaking process at a later time. Public notice and an opportunity to comment on that proposal will be provided.  In the meantime, the existing NSRL of 2 µg/day for ethylene oxide adopted in Title 27, California Code of Regulations Section 25705(b) remains in effect.

Extension of Public Comment Period

OEHHA is withdrawing the proposed updates to the No Significant Risk Level for ethylene oxide.

Modification to the Proposed Regulation and Public Comment Period

On April 7, 2023 OEHHA proposed to update the Proposition 65 no significant risk level for ethylene oxide in Cal. Code of Regs., Title 27, Section 25705(b)(1). OEHHA is now modifying the regulatory proposal by limiting the originally proposed update to the NSRL to the inhalation route and by proposing a separate NSRL for the oral route. The numerical values of the proposed NSRL are 0.058 micrograms per day for the inhalation route and 1.5 micrograms per day for the oral route. This modification is based on comments received on the April 2023 proposal and the available scientific literature.

OEHHA opened a public comment period for comments on the modification and addition of a document to the rulemaking file. The comment period was scheduled to end on January 10, 2024, but has been extended to January 17, 2024.

Below is a notice that summarizes the proposed modification, provides reference to the document added to the record, and gives instructions on providing public comment. The notice is followed by the modified proposed regulatory text.

Original Proposed Rulemaking

OEHHA first proposed the regulation by publishing a Notice of Proposed Rulemaking in the California Regulatory Notice Register (CRNR) on April 7, 2023. In parallel, OEHHA issued an Initial Statement of Reasons and proposed regulatory text for the proposal. OEHHA provided a public comment period on the original proposal, from April 7, 2023 to June 14, 2023.