On July 14, 2017, Oregon Department of Environmental Quality (DEQ) issued a proposed rulemaking regarding the air toxic ambient benchmarks codified in Oregon Administrative Rule (OAR) 340-246-0090. DEQ is proposing changes to 23 of the 52 ambient benchmarks in OAR 340-246-0090 based on a review of new toxicity information conducted by the Air Toxics Science Advisory Committee (ATSAC). Highlights of the proposed rule include:

  • The benchmark for trichloroethylene is proposed to decrease from 0.5 to 0.2 µg/m3,
  • Formaldehyde benchmark is proposed to decrease from 3 to 0.2 µg/m3,
  • Acrolein benchmark is proposed to increase from 0.02 to 0.35 µg/m3,
  • Benchmarks were added for phosgene, n-propyl bromide, and styrene,
  • Polycyclic aromatic hydrocarbons (PAHs) list is proposed to be revised from 32 individual PAHs to 26 PAHs with revised toxicity-adjusted benchmark values, and
  • Diesel particulate matter and lead benchmarks were retained without change.

A red-lined version of the existing rule that identifies the changes to the ambient benchmarks is provided in the proposed rulemaking.

As stated in the proposed rulemaking, the ambient benchmark concentrations in OAR 340-246-0090 may be adopted into the risk-based air toxics permitting program, Cleaner Air Oregon, as risk-based concentrations. The Advisory Committee for the Cleaner Air Oregon toxics program will be meeting on July 28, August 29, and August 30, and the proposed program rules are expected to be released this summer.

DEQ will accept public comments on the proposed OAR 340-246 rulemaking until 4:00 PM on August 21, 2017 and will hold a public hearing on August 17, 2017 at 9:30 AM. The hearing will be held at 700 NE Multnomah St., Suite 600, Third Floor, Conference Room A, Portland, OR 97232. Information about the proposed rulemaking and a link for submitting comments can be found on DEQ's website.

Contact Ashley Jones at (253) 867-5600 for more information.