Colorado Adopts Health-based Protections from Cancer-Causing Toxic Air Pollutants

(Denver, CO - September 22, 2025) - On Friday, the Colorado Air Quality Control Commission voted unanimously to adopt health-protective benchmarks to protect communities from toxic air pollutants. These new benchmarks consider both cancer and non-cancer-related health risks such as asthma, respiratory illness, reproductive and developmental harms. A protective one-in-one million cancer risk level was adopted along with a more protective toxicity value for the non-cancer benzene benchmark. However, the chronic non-cancer benchmarks were weakened for the other pollutants.

"This rule has promise to benefit the health of vulnerable communities in the face of federal rollbacks to environmental protections," said Meagan Weisner, Senior Scientist for EDF Healthy Communities. "Although results were not as protective as we wanted for the non-cancer benchmarks, there is still important work ahead to address acute exposures that cause other health harms. We urge the state to enact rigorous implementation that will deliver health benefits for Coloradans living, working and playing at the fence line of industrial pollution."

The new rule is based on Colorado's 2022 Public Protections for Toxic Air Contaminants Act, which directed the Commission to propose health-based standards that consider the effects on vulnerable groups by April 2026.

Friday's ruling set health-protective benchmarks to protect Coloradans from five air toxics and their associated health risks:

• Benzene - cancer (leukemia), blood disorders, weakened immune system, reproductive issues, developmental harm
• Formaldehyde - cancer (nose, leukemia), respiratory effects, developmental harm
• Hydrogen sulfide - Neurological, cardiovascular, and respiratory effects
• Ethylene oxide - Cancer (leukemia, lymphoma, breast), reproductive issues
• Hexavalent chromium - Respiratory effects (including asthma), kidney and liver disease, cancer

  To speak with Meagan Weisner on this ruling, its health benefits and toxic air pollution from the oil & gas sector, please contact Cecile Brown at (202) 271-6534 or [email protected].