Industry impacts from potential air toxics regulations
Published on October 20, 2025
Which Weld County Places and Industries Could Be Affected by New Emission Control Regulations?
Colorado has been developing its air toxics program since 2022, which includes air monitoring, reporting, identifying “priority air toxics,” setting health-protective benchmarks, and conducting a permit assessments. New developments in the program, creating emission control regulations, could impact certain industries in Weld County.
What are "Air Toxics"?
Air toxics are pollutants that, depending on concentrations and lengths of exposure, can cause or contribute to cancer, heart disease, organ damage, birth defects, or other serious health effects.
Under House Bill 1244, passed in 2022, the Air Quality Control Commission (AQCC) must consider emission control regulations for five Priority Toxic Air Contaminants (PTACs) by April 2026:
- Hydrogen sulfide
- Ethylene oxide
- Benzene
- Formaldehyde
- Hexavalent chromium
Let’s look at how each of these PTACs and potential regulations impact Weld County.
Hydrogen Sulfide: Agriculture and Energy
Hydrogen sulfide is a PTAC receiving close attention. Hydrogen sulfide is produced through the breakdown of organic material — such as manure or petroleum byproducts. In Weld County, this means operations that manage manure could be affected. The Platte River Biogas Facility near La Salle currently reports the highest hydrogen sulfide emissions in the county due to its manure-based anaerobic digestion process. Depending on where the state sets emission limits, other potentially affected sectors could include:
- Municipal wastewater treatment facilities
- Dairy farms and feedlots
- Landfills
- Oil and gas operations
Ethylene Oxide: Medical Equipment Sterilization
At the federal level, ethylene oxide regulation continues to be a subject of significant debate. It is an important sterilizing agent for medical equipment that can’t be cleaned through other methods. Weld County does not have any large ethylene oxide users, but there is a major facility in Larimer County, Jorgensen Laboratories operating in Loveland. Two local facilities in Windsor, Metal Container Corporation and Vestas-American Wind Technology, reported only minimal emissions in 2024. Whether they’ll be affected by new regulations remains to be seen.
Benzene and Formaldehyde: Byproducts of Combustion
Whenever something burns —wood, fuel, or natural gas —small amounts of benzene and formaldehyde are produced. Formaldehyde can also form naturally in the atmosphere. Cleaner, more complete combustion (when enough oxygen, heat, and time are present) reduces these emissions. While perfect combustion isn’t possible, industry has made steady progress in efficiency and control.
Because combustion powers everything from vehicle engines to home heating, it’s difficult to know exactly who will be affected by new rules. Regulations are expected to focus primarily on oil and gas operations, though they could also touch other industries using engines, generators, or stoves.
Hexavalent Chromium: Minimal Local Impact
Weld County has no major sources of this pollutant. The nearest plant, Rawhide Energy Station Unit 1 in northern Larimer County, is already scheduled to close before 2031 and is therefore exempt from new AQCC regulations under House Bill 1244.
While naturally occurring chromium (III) is common in soils and rocks, almost all hexavalent chromium (chromium VI) emissions in Colorado come from coal-fired power plants.
Learn More and Share Your Input
The Air Pollution Control Division (APCD) will host two virtual public meetings to explain proposed emission control strategies and the industries that may be affected:
- Wednesday, October 22
- Saturday, November 8
Both meetings will include time for questions and public comment.
Visit the Weld County Air Events Calendar for details and links to register.
If you’d like help preparing a public comment or have other questions on how to get involved, contact Dr. Annareli Morales at the Weld County Department of Public Health and Environment at amorales@weld.gov.
What’s Next?
The APCD recently released a Regulatory Concepts Document outlining potential control strategies. A request for rulemaking will then go before the AQCC at its December 17 to 19 meeting. The formal rulemaking hearing for PTAC emission control regulations is tentatively scheduled for April 16 - 17, 2026.
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