Toxic Air Contaminants

What are Toxic Air Contaminants?

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.

CDPHE Air Toxics Program

The Colorado state legislature passed two key pieces of legislation that reinforce the state's commitment to protecting public health by significantly expanding the air monitoring program for TACs:

  • House Bill (HB) 21-1189, signed into law on June 24, 2021, relating to Public Health in Relation to the Emission of Air Toxics; and
  • HB22-1244, signed into law on June 2, 2022, relating to Public Protections from Toxic Air Contaminants

Information on HB21-1189 Air Toxics Act

Information on HB22-1244 Protections from Toxic Air Contaminants

HB21-1189 Key Features

  1. Creates a required fenceline monitoring program at four covered facilities, which includes a public emergency notification system.
  2. Creates a community monitoring program designed to measure emissions in communities surrounding the covered facilities.
  3. Ensures that all data from the fenceline and community monitoring programs are made available to the public.

Information on HB21-1189 Air Toxics Act



HB22-1244 Key Features

  1. Creates an annual TAC emissions reporting program.
  2. Creates a TAC monitoring program.
  3. Creates a program to establish health-based standards for priority TACs.
  4. Allows for TAC emission control regulations.
  5. Establishes a TAC permitting needs assessment program.

Information on HB22-1244 Protections from Toxic Air Contaminants

By October 1st, 2022, APCD is required to post an initial list of covered toxic air contaminants.  The initial list of Toxic Air Contaminants can be found here:

Initial List of Toxic Air Contaminants