Proposed rule
Rulemaking contact:
Apollonia Riberdy, 503-869-0026
The Oregon Department of Environmental Quality is proposing to review and update the rules focused on exposure to toxic air contaminants in the state of Oregon.
DEQ and the Oregon Health Authority are required
by rule to review the best available science and convene an Air Toxics Science Advisory Committee, or ATSAC, to evaluate the need for and propose changes to rules regarding toxic air contaminants. Specifically, the rulemaking will focus on updates to the Priority Toxic Air Contaminant List, the Toxicity Reference Values, and the Risk-Based Concentrations used to regulate toxic air contaminant emissions from permitted facilities in Oregon under the Cleaner Air Oregon program.
Background
In November 2021, the Environmental Quality Commission approved the Air Toxics Alignment Rules, which established the
Health Risk-Based Air Quality Standards for Toxic Air Contaminants. These rules establish the:
- Priority Toxic Air Contaminant List that establishes what emissions regulated facilities must report to DEQ.
- Toxicity Reference Values are air quality benchmarks used to evaluate the potential health risks from inhaling toxic air contaminants.
- Authoritative sources DEQ can use as the best available science to develop the priority list and Toxicity Reference Values.
- Criteria for appointing members of the public to serve on the ATSAC, including requirements around skills, experience and avoiding conflicts of interest.
- Role and scope of the ATSAC.
- Process for periodically reviewing and updating this information.
Additionally, Cleaner Air Oregon, DEQ's health risk-based permitting program, uses Risk-Based Concentrations, or RBCs to evaluate the health risk of certain pollutants. The Risk-Based Concentrations are based on the Toxicity Reference Values and adjusted based on a number of factors that affect how much risk a particular pollutant poses.
For this rulemaking DEQ and OHA reviewed the Priority List, the Toxicity Reference Values, and Risk-Based Concentrations tables to determine what updates are needed to keep these tables up to date with the best available data needed to issue air quality permits that meet health-based standards.
Rulemaking scope
DEQ is seeking input and feedback from the Rules Advisory Committee on the following items:
Advisory committee
Since this rulemaking requires significant review of highly technical scientific information to develop the proposed rule updates, DEQ and OHA split this process into two phases. First, the scientific review, including convening and consulting with the ATSAC. Second, the formal rulemaking process that includes convening the Rules Advisory Committee and Fiscal Advisory Committee.
Phase 1 extended from November 2021 until May 2025 to finalize the proposed revisions. For information related to ATSAC meetings and phase 1 timeline events, please visit the Air Toxics Science Advisory Committee website.
Phase 2 is now underway. DEQ has planned for three Rules Advisory Committee meetings and a separate Fiscal Advisory Committee meeting. Meeting materials, agendas, and links will be posted here within a week of each meeting.
Meeting #1 – Kickoff Meeting: Monday, Jan. 12, 2026, 9 a.m. to noon.
Meeting #2 – Proposed rules discussion: Monday, Feb. 23, 2026, 9 a.m. to noon.
Meeting #3 – Proposed rules discussion: Wednesday, Feb. 25, 2026, 9 a.m. to noon.
Meeting #4 – Rule Implementation and Fiscal Advisory Committee: Monday, March 16, 2026, 9 a.m. to noon.