Uniform Small Off-Road Engine Emissions Standards Act of 2025

This Act finds that a uniform national standard for emissions from small off-road engines (SOREs) is necessary to protect interstate commerce by reducing compliance costs for manufacturers and preventing regulatory fragmentation. Within 180 days of enactment, the Administrator of the Environmental Protection Agency (EPA) shall issue a final rule establishing national emissions standards for SOREs that are at least as stringent as the standards approved by the EPA for California in 2024. No state or political subdivision may adopt or enforce emissions standards for SOREs that are more stringent than the federal national standards, provided that any state may petition the EPA for a waiver of this preemption if the state demonstrates that (1) its air quality is significantly worse than the national average as measured by the National Ambient Air Quality Standards, (2) the state's proposed standards are necessary to achieve attainment of those standards, and (3) the state's standards do not impose an undue burden on interstate commerce. The EPA shall approve or deny such a waiver petition within 180 days of submission. Enforcement of the national standards shall be carried out by the EPA through civil penalties of up to $10,000 per violation for manufacturers. States that adopt or enforce more stringent standards in violation of this preemption shall have a percentage of their federal highway funds withheld, as determined by the Secretary of Transportation. This Act shall sunset 10 years after enactment, and the EPA shall submit a report to Congress on the effectiveness of the national standards and the waiver process no later than 9 years after enactment.