Today's action supports EPA's comprehensive approach to address climate and health-harming pollution from stationary combustion turbines. EPA is engaging with stakeholders on next steps for a broad-based approach to new and existing combustion turbines, including a proposed revision to the air toxics standards for combustion turbines as well as separate rulemakings to address ozone-forming pollution from new combustion turbines and to establish greenhouse gas emission guidelines for existing combustion turbines.
EPA's section 112 regulations limit emissions of air toxics, also called hazardous air pollutants, such as formaldehyde, toluene, benzene, acetaldehyde, and metallic HAP (e.g., cadmium, chromium, manganese, lead, nickel). HAP are known to cause – or are suspected to cause – cancer or other serious adverse health and environmental effects. Formaldehyde and acetaldehyde are probable human carcinogens.
Petitioners requested EPA remove, or "delist," combustion turbines, saying that cancer risks from this source category were below 1-in-1 million and would meet the statutory "delisting" threshold. EPA has reviewed data and analyses submitted as part of this petition as well as additional emissions testing data. EPA is denying the petition based on the agency's determination that the petition is incomplete and because EPA cannot conclude that there are adequate data to determine that the delisting thresholds in the Clean Air Act have been met. This is primarily due to both the uncertainty in the HAP emissions from affected sources and the missing emissions data from a large number of affected sources in the petitioners' risk analysis.
A pre-publication version of the notice and a fact sheet are available on the Stationary Combustion Turbines: National Emission Standards for Hazardous Air Pollutants webpage.
