Criteria Air Pollutants
The Clean Air Act requires the U.S. Environmental Protection Agency (EPA) to establish national air quality standards for six common air pollutants that are found throughout the United States. EPA refers to these pollutants as “criteria” pollutants because they are regulated by using human health-based and/or environmentally-based criteria to set permissible levels. The levels set by EPA are known as National Ambient Air Quality Standards (NAAQS).
Other Air Pollutants | Top
Some airborne contaminants that do not fall into EPA's criteria air pollutant categories are of interest in Utah.
Nonattainment of National Standards | Top
Areas are categorized based on whether they meet National Ambient Air Quality Standards (NAAQS)
- Attainment areas: regions that meet the NAAQS
- Nonattainment areas: regions that do not meet the national air standards
- Maintenance areas: former nonattainment areas that have improved air quality so it is no longer violating the NAAQS and adopted an EPA approved plan to maintain the standards
- Maintenance areas retain this classification for 20 years