Toxic Air Contaminant List

The Colorado Revised Statutes (CRS) define Toxic Air Contaminants (TACs) as:

1. A hazardous air pollutant, also known as toxic air pollutants or air toxics, are those pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects, as defined by the EPA;
2. Covered air toxic, which includes hydrogen cyanide (HCN), hydrogen sulfide (H₂S), and benzene (C₆H₆) as defined in CRS §25-7-141(2)(b); or
3. Any other air pollutant that the commission designates as a toxic air contaminant pursuant to subsection (3) of CRS §25-7-109.5.

The Colorado Revised Statutes (CRS) define Toxic Air Contaminants (TACs) as:

• A hazardous air pollutant, also known as toxic air pollutants or air toxics, are those pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects, as defined by the EPA;
• Covered air toxic, which includes hydrogen cyanide (HCN), hydrogen sulfide (H2S), and benzene (C6H6) as defined in CRS §25-7-141(2)(b); or
• Any other air pollutant that the commission designates as a toxic air contaminant pursuant to subsection (3) of CRS §25-7-109.5.

The TAC list provided above satisfies §3 of HB22-1244, and was compiled from the following sources:

• Colorado Revised Statutes, §25-7-109.3 and §25-7-141(2)(b); and
• Air Quality Control Commission Regulation Number 3; and
• EPA Hazardous Air Pollutants (HAPs) List; and
• EPA Toxic Substance Control Act (TSCA) for 1-bromopropane; and
• EPA National Air Toxics Trends (NATTS) Network
  • Sites
  • Technical Assistance Document (TAD)
  • Work plan template

The Air Pollution Control Division (Division) published the initial list of TACs in October 2022 as required by HB22-1244. The Division discovered administrative errors including where some TACs were listed in duplicate or had typographical errors in the spelling of a compound or the chemical identifier (CAS#). The revised December 2023 list corrects those errors.