The undersigned associations urge you to ensure the Environmental Protection Agency maintains existing National Ambient Air Quality Standards for fine particulate matter (PM2.5). A proposed discretionary revision to this standard, which is under review by the Office of Information and Regulatory Affairs, could put nearly 40% of the U.S. population in areas of nonattainment. Doing so would risk jobs and livelihoods by making it even more difficult to obtain permits for new factories, facilities and infrastructure to power economic growth. This proposal would also threaten successful implementation of the Infrastructure Investment and Jobs Act, the CHIPS and Science Act and the important clean energy provisions of the Inflation Reduction Act. Our members have innovated and worked with regulators to lower PM2.5 concentrations significantly, and further progress is being made as part of the energy transition investments. The EPA recently reported that PM2.5 concentrations have declined by 42% since 2000, driven by major emissions reductions from both mobile sources and the power sector. As a result, America’s air is cleaner than ever. The current standard for PM2.5 is set at 12 μg/m3 ; yet, the EPA is considering a standard as low as 8 μg/m. Such a standard would be lower than ambient concentrations in many parts of the country and far more stringent than the 25 μg/m European Union standard.