Governor Kate Brown launched the Cleaner Air Oregon rulemaking process in April 2016 after communities around the state raised concerns about their exposure to potentially harmful heavy metals, chemicals and other pollutants from factories and other industrial sources. Oregon's existing rules were based on federal law. These existing rules allowed industrial facilities to release potentially harmful amounts of air toxics, but still operate within legal requirements.

The Environmental Quality Commission adopted Cleaner Air Oregon rules in November 2018 to close the regulatory gaps left after the implementation of federal air toxics regulations. Cleaner Air Oregon is a state health risk-based air toxics regulatory program that adds requirements to DEQ’s existing air permitting framework.