US EPA announces ‘historic’ rollback of air emissions regulations
13 March 2025
The Administrator of the US Environmental Protection Agency (EPA), Lee Zeldin, announced the agency will undertake “31 historic actions in the greatest and most consequential day of deregulation in US history,” to advance the policies of President Trump’s administration. These actions will roll back trillions in regulatory costs and hidden “taxes”—the EPA said in a press release. The deregulation is intended to unleash American energy, lower the cost of living and operating a business, revitalize the American auto industry, restore the rule of law, and give power back to states to make their own decisions.
The EPA has announced the planned actions in a series of some 25 press releases dated March 12, 2025. While the primary target of deregulation are GHG emissions, the agency will also reconsider and relax certain criteria pollutant regulations. The key actions that affect engine and vehicle regulations include:
- The EPA will commence a formal reconsideration of the 2009 Endangerment Finding in collaboration with the Office of Management and Budget (OMB) and other agencies. The Endangerment Finding is a formal determination made under the Clean Air Act, following the 2007 Supreme Court ruling that CO2 is a pollutant and can be regulated. The EPA Endangerment Finding states that GHGs pose a threat to public health and welfare and therefore should be regulated. The finding identified six GHGs—carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulfur hexafluoride (SF6)—as contributing to climate change through their accumulation in the atmosphere.
- The EPA will reconsider model year 2027 and later GHG emission standards for light- and medium-duty vehicles and Phase 3 GHG emission standards for heavy-duty vehicles. Both regulations require an increasing market penetration of zero emission vehicles in the respective light- and heavy-duty sectors and provide “the foundation for the Biden-Harris electric vehicle mandate.”
- Additionally, the EPA is reevaluating the other parts of the “Clean Trucks Plan,” including the 2027 NOx emission standards for heavy-duty engines and vehicles.
- The agency will reconsider multiple National Emission Standards for Hazardous Air Pollutants (NESHAP) affecting a broad range of industrial sectors—including emissions from stationary diesel and natural gas engines.
- The EPA is revisiting the National Ambient Air Quality Standards (NAAQS) for PM2.5, which “have raised serious concerns from states across the country and served as a major obstacle to permitting.”
Several of the announced actions would deregulate the energy sector. In particular, the EPA will reconsider the mandatory Greenhouse Gas Reporting Program (GHGRP); the Clean Power Plan 2.0 regulation; the wastewater regulations from oil and gas extraction; the Coal Combustion Residuals (coal ash) program; and other regulations.
While the announcements do not cover California emission regulations, the EPA has ordered a review of waivers granted to CARB for the Advanced Clean Trucks (ACT) and Omnibus NOx regulations.
Source: US EPA