EPA Loosens Rules, Limits States’ Authority
The Environmental Protection Agency (EPA) recently has made various decisions that reverse some state and local air district regulations and diminish their regulatory authority.
EPA Repeals Endangerment Finding
In 2009, the EPA issued the Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Clean Air Act (Endangerment Finding), determining that emissions of Greenhouse Gases (GHGs) from new motor vehicles and engines contribute to air pollution that may reasonably be anticipated to endanger public health and welfare under Section 202(a) of the Clean Air Act (CAA). The former finding specified that six key “well-mixed” greenhouse gases – carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6) – in the atmosphere threaten the public health and welfare of current and future generations. In the years following, the Endangerment Finding served as the legal prerequisite for many GHG vehicle regulations for cars, trucks and certain categories of engines, including electric vehicle mandates.
On July 29, 2025, the EPA announced a proposal to rescind the 2009 Greenhouse Gas Endangerment Finding. Since the Endangerment Finding is a prerequisite for regulating emissions from new motor vehicles and new motor vehicle engines, absent this finding, the EPA lacks statutory authority under Section 202 of the Clean Air Act to prescribe standards for GHG emissions. Therefore, the EPA also proposed to remove GHG regulations for light-, medium- and heavy-duty on-highway vehicles. As a result of these proposed changes, engine and vehicle manufacturers would no longer have any future obligations for the measurement, control and reporting of GHG emissions for any highway engine and vehicle, including model years manufactured prior to this proposal.
The rescission became final in February of this year, with the EPA concluding that even if the US were to eliminate all GHG emissions from all vehicles, there would be no material impact on climate change. California’s Governor submitted a formal comment to the US EPA officially opposing the administration’s efforts to “gut America’s foundational clean air protections.” He said in a statement that California would take the Trump administration to court over the decision.
California’s EV Mandate Blocked
The EPA revoked waivers that allowed California to enforce stricter vehicle emission rules and a 2035 ban on new gasoline cars. California and multiple states are pursuing legal action to reverse the action. The United States Department of Justice (DOJ) has filed suit on behalf of the National Highway Traffic Safety Administration (NHTSA) to stop California from imposing an electric vehicle (EV) mandate through what the DOJ considers “state-specific mileage requirements for car manufacturers.” This case challenges the state’s regulations as preempted under the Energy Policy and Conservation Act, which, according to the complaint, makes NHTSA the exclusive regulator of fuel economy in the United States.
Natural Gas Ban Disputes
An effort by the South Coast Air Quality Management District (SCAQMD) that essentially would have banned natural gas for residential space and water heaters failed when the agency’s governing board rejected Proposed Amended Rules 1111 — Reduction of NOx Emissions from Natural-Gas-Fired, Fan-Type Central Furnaces and 1121 — Control of Nitrogen Oxides from Residential Type, Natural-Gas-Fired Water Heaters. The agency typically tackles one rule at a time, but in recent rulemakings, staff have been proposing rule “bundles” that impact multiple types of equipment. Prior to the public hearing for the rules, the United States Department of Justice sent a letter to the SCAQMD stating, “The United States government is committed to the removal of illegitimate impediments to the use of domestic energy resources, including natural gas.” Furthermore, the letter threatened legal action against SCAQMD if it adopted the rules.
TSCA Relaxation
The EPA has proposed changes to its reporting requirements for perfluoroalkyl and polyfluoroalkyl substances (PFAS) under the Toxic Substances Control Act (TSCA). According to the agency, the proposal aims to make the PFAS reporting rule easier to implement and reduce unnecessary or duplicative reporting burdens on businesses while still allowing the agency to gather key information about PFAS uses and potential health and environmental effects. The proposed exemptions are PFAS manufactured (including imported) in mixtures or products at concentrations 0.1% or lower; imported articles; certain byproducts; impurities; research and development chemicals; and non-isolated intermediates.
Public comments on the rule closed in December 2025, and the EPA is expected to issue a final rule in 2026.
Rita Loof
director of regional environmental affairs,
RadTech International North America
rita@radtech.org
