OAR 340-246-0090: Ambient Benchmark Concentrations for Toxic Air Contaminants

Purpose. Ambient benchmark concentrations are concentrations of toxic air contaminants that serve as goals in the Oregon Toxic Air Contaminants Program. They are based on human health risk and hazard levels considering sensitive populations. Ambient benchmark concentrations are not regulatory standards, but reference values by which toxic air contaminant problems can be identified, addressed and evaluated and are numerically equivalent to the “Toxicity Reference Value” as defined under OAR 340 247-0020 . DEQ will use ambient benchmark concentrations as indicated in these rules, to implement the Geographic and Source Category Programs. Ambient benchmark concentrations set by the procedures described in this rule apply throughout Oregon, including that area within the jurisdiction of the Lane Regional Air Protection Agency.