The Colorado Air Quality Control Commission has adopted measures to control emissions of five priority air toxic contaminants, including hexavalent chromium compounds from finishing and coating operations.
Michael OgletreeThe CAQCC says certain facilities in Colorado that emit these pollutants will have to reduce emissions by implementing new technologies, adjusting work practices, and using less-toxic materials.
The regulations aim to reduce priority air toxic contaminants from key sources that emit them:
- Hexavalent chromium from decorative and functional chrome plating.
- Benzene from petroleum refineries.
- Formaldehyde from stationary spark-ignition reciprocating internal combustion engines and combustion turbines.
- Ethylene oxide from sterilization facilities.
- Hydrogen sulfide from asphalt processing, roofing products, and manure digesters.
“This is a big step in our work to protect the health of all Coloradans,” says CDPHE Senior Director of State Air Quality Programs Michael Ogletree. “More oversight and control measures from key sources of air toxics will help ensure we all have clean air. This progress would not have been possible without input from stakeholders. They helped us to devise programs that will protect public health while preserving economic growth.”
The new rules outlaw any new finishing operations from using baths of hexavalent chromium. Much of what the CAQCC adopted came from the California Air Resources Board (CARB) Airborne Toxic Control Measure for Chromium Electroplating and Chromic Acid Anodizing Operations.
In 2024, CARB imposed strict new rules on finishers that will effectively force the closure of many chromium-using metal-finishing operations.
While new hex chrome lines will be banned, those with existing finishing operations will also face new regulations that include:
- Installation of new or enhanced emissions control technologies.
- Substitution of less hazardous materials where feasible.
- Modifications to existing processes to reduce air toxic emissions.
For electroplaters, the rules will increase scrutiny of fume-suppression systems, mist eliminators, scrubbers, and work practices associated with hexavalent-chromium baths. Facilities that have already transitioned to trivalent chromium systems or implemented advanced emission controls may be better positioned, while shops still relying on legacy systems could face higher compliance costs.
The proposed rulemaking was part of the state’s effort to implement House Bill 22-1244, the Public Protection from Toxic Air Contaminants Act. The legislation directs the state to identify, prioritize, and reduce emissions of air toxics that pose elevated risks to public health—particularly in communities disproportionately impacted by industrial pollution.
The CDPHE Air Pollution Control Division says it conducted extensive outreach while developing the proposal, including public meetings, site visits, and engagement with impacted industries and other stakeholders to explain the proposal and gather feedback.
The commission will revisit and consider adding pollutants to the list of priority air toxic contaminants and to the list of emission control measures every five years.
Visit https://cdphe.colorado.gov.
