The US Environmental Protection Agency (EPA) reinstated California’s authority under the Clean Air Act to implement its own greenhouse gas (GHG) emission standards and zero emission vehicle (ZEV) sales mandate. This means that the Clean Air Act (CAA) waiver granted to California to implement its Advanced Clean Car (ACC) program in 2013 is back in force.

The ACC program is a package of state regulations that set emissions standards for criteria pollutants and greenhouse gas (GHG) emissions for light-duty vehicles and a zero-emission vehicle (ZEV) sales mandate.

This action concludes the agency’s reconsideration of 2019’s Safer Affordable Fuel-Efficient Vehicles Rule Part One: One National Program Rule (SAFE-1) by finding that the actions taken under the previous administration as a part of SAFE-1 were decided in error and are now entirely rescinded.

With the action, EPA is also withdrawing the SAFE-1 interpretation of the Clean Air Act that would prohibit other states from adopting the California GHG emission standards. As a result, other states may choose to adopt and enforce California’s GHG emission standards in lieu of the Federal standards, consistent with section 177 of the Clean Air Act.