US: Section 177 States


Due to its vehicle regulations that preceded the federal Clean Air Act (CAA) of 1970 and its particularly severe motor vehicle-related air quality air issues, the state of California retains the unique authority as a U.S. state to set emission standards. As a result, under federal law, any California vehicle emissions standards must meet or exceed federal emission regulations. Under the Federal Air Quality Act and Section 209 of the CAA, the State of California is required to request, and be granted a waiver from the US Environmental Protection Agency (EPA) Administrator in order to implement any proposed standards. Under this provision, the California Air Resources Board (CARB) has requested and received over 50 waivers.

Although States besides California are not permitted to develop their own emissions standards, Section 177 of the Clean Air Actauthorizes other States to choose to adopt California’s standards in lieu of federal requirements. States are not required to seek EPA approval before adopting California’s standards. Currently, 15 States have done so. These States are known as “Section 177 States.”

Adopting States

The 15 Section 177 States are as follows:

  • Connecticut
  • Maine
  • Maryland
  • Massachusetts
  • New Jersey
  • New Mexico
  • New York
  • Oregon
  • Pennsylvania
  • Rhode Island
  • Vermont
  • Washington
  • Delaware
  • Georgia
  • North Carolina

Note: some of these States have adopted California requirements for only certain classes of vehicles. For further detail, refer to EPA’s guidance on cross-border sales, in particular the 2011 memo, “Sales of California Vehicles for 2011 Model Year and Beyond.

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