Colorado regulators are moving forward with a new round of environmental rulemaking that could significantly affect electroplating and anodizing operations using hexavalent chromium.
The move could eliminate any new electroplating operations that wants to use hexavalent chromium, and also put severe limits on existing facilities.
“The proposed rules, for example, would outlaw any new operations from using baths of hexavalent chromium,” says Ed Sealover, who writes for the online news site published by the Colorado Chamber of Commerce. “Companies who will come under the regulations will be those who emit the pollutants above a certain threshold — 10,000 pounds a year of hydrogen sulfide, 4,000 pounds annually for benzene and formaldehyde and any amount of hexavalent chromium.”
Even worse news for the finishing industry is that the Colorado Air Quality Control Commission says it will adopt language from the California Air Resources Board (CARB) Airborne Toxic Control Measure for Chromium Electroplating and Chromic Acid Anodizing Operations in its new regulations.
In 2024, CARB imposed strict new rules on finishers that will effectively force the closure of many chromium-using metal-finishing operations.
During its December meeting, the Colorado Air Quality Control Commission voted to hold a formal rulemaking hearing in April 2026 to consider new emissions control requirements for several “priority air toxic contaminants,” including hexavalent chromium compounds.
The proposed rulemaking is being developed by the Colorado Department of Public Health and Environment’s Air Pollution Control Division as 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.
Focus on Priority Air Toxics
The commission has identified five priority air toxic contaminants that will be addressed in the April 2026 hearing:
- Formaldehyde
- Benzene
- Hexavalent chromium compounds
- Ethylene oxide
- Hydrogen sulfide
“Colorado is meeting its legislative mandate to establish health benchmarks for priority air toxics,” says Michael Ogletree, Senior Director of State Air Quality Programs. “By using leading science and input from both communities and industry, the state has created public health benchmarks that could help guide future policy conversations while providing clarity today about exposure levels.”
Under the division’s proposal, certain sources of these priority air toxics would be required to implement additional emissions reduction measures. For hexavalent chromium, the proposed regulated sources explicitly include chrome plating and anodizing operations.
What the Proposed Rule Could Require
While specific control limits and compliance details are expected to be refined ahead of the April hearing, the Air Pollution Control Division has indicated that regulated facilities may be required to adopt one or more of the following strategies:
- 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, this could mean increased 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.
Broader Industrial Impact
In addition to chrome plating and anodizing, the proposed rule targets several other industrial source categories, including:
- Anaerobic digesters using manure feedstock.
- Asphalt and asphalt roofing product manufacturing.
- Sterilization facilities.
- Gas-fired stationary spark ignition engines.
- Combustion turbines.
- Petroleum processing and refining operations.
The inclusion of metal finishing alongside these large industrial sources underscores heightened regulatory scrutiny of hexavalent chromium emissions, even from smaller or mid-sized operations.
Expanded Reporting Requirements
Beyond emissions controls, the commission will also consider enhanced reporting requirements at the April hearing. These requirements are intended to improve the state’s understanding of where and how priority air toxics are emitted.
Additional reporting could apply to a broader range of sources, including certain domestic and industrial wastewater treatment plants. According to the Air Pollution Control Division, this expanded data collection may be used to identify future control strategies and regulatory actions.
For metal finishers, this raises the possibility of increased documentation, emissions tracking, and reporting obligations—even for facilities that may not immediately fall under new control requirements.
For information, visit https://cdphe.colorado.gov/air-toxics/priority-toxic-air-contaminants#emissionreg.
