During its December meeting, the Colorado Air Quality Control Commission agreed to hold a rulemaking hearing in April 2026 to consider emissions control regulations for priority air toxics. By creating and proposing this rule, the Air Pollution Control Division will help carry out the requirements of House Bill 22-1244: The Public Protection from Toxic Air Contaminants Act.

The commission previously identified five priority toxic air contaminants: formaldehyde, benzene, hexavalent chromium compounds, ethylene oxide, and hydrogen sulfide. Air toxics are pollutants that cause or are suspected of causing cancer, birth defects, and other negative health impacts. The division’s proposed rule would require that certain sources of priority air toxic contaminants use measures such as new technologies, substituting less hazardous materials, and modifying processes to reduce emissions. The proposed sources are:

· Chrome plating and anodizing.

· Anaerobic digesters with manure feedstock.

· Asphalt or asphalt roofing product manufacturing.

· Sterilization facilities.

· Gas-fired stationary spark ignition engines.

· Combustion turbines.

· Petroleum processing and refining operations.

At the hearing, the commission will also consider reporting requirements to enhance existing information about the priority air toxics from additional sources, including certain domestic and industrial wastewater treatment plants. This information may be used to identify opportunities for future control strategies.

While developing the proposal, the division took several steps, including:

· Analyzing how to prioritize reductions in disproportionately impacted communities that have multiple sources of priority air toxics.

· Reviewing similar regulations from other states and the federal government.

· Considering which measures are technically and economically feasible.

· Holding numerous meetings, including public meetings and site visits, with impacted industries and other stakeholders to explain the proposal and solicit feedback.

There are opportunities to learn more and get involved in the rulemaking process with the Air Quality Control Commission:

· Review materials related to the rulemaking request and hearing. The commission will add more materials to the folder leading up to the April meeting.

· Become a party to the rulemaking hearing. More information is available on the commission’s web page on what party status means and how the process works.

· Submit written comments directly to the commission at cdphe.aqcc@state.co.us.

· Register to offer a verbal public comment or listen to the April 2026 rulemaking hearing. More information is available on the commission’s web page.