State- and Territory- Specific Standards

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State Fuels

The Clean Air Act (CAA) establishes national fuel emission standards, but also allows states, with some restrictions, to adopt unique fuel programs to meet local air quality needs.  The combination of federal and state fuel programs is intended to balance the importance of standard fuel quality across the country with the need for sufficient flexibility to address specific air quality issues at the state or local level.  These state or local specific fuel programs are often referred to as "boutique fuels."  EPA maintains a list of states with boutique fuel programs, including the Petroleum Administration for Defense Districts (PADDs) in which they are used. 

The following is the only state-specific controls applied to diesel fuel:

Type of Fuel Control PADD Region - State
Low Emission Diesel 3 6 - TX


Under EPA’s Highway Diesel and Nonroad Diesel rules, rural areas of Alaska were allowed to transition all highway, non­road, locomotive, and marine diesel fuel to the 15 parts per million (ppm) ultra-low sulfur diesel (ULSD) sulfur specification starting June 1, 2010. This streamlined transition approach was designed to ensure that the rural areas of Alaska would have ULSD by al­lowing all of the fuel to transition to ULSD at the same time.

Learn more about Alternative Low-Sulfur Diesel Fuel Transition Program for Alaska.

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U.S. Territories: Mariana Islands, Guam, American Samoa

The Mariana Islands, Guam and American Samoa are exempt from the sulfur content requirement for motor vehicle diesel fuel, regulated under the CAA. EPA granted exemptions to each of the three U.S. territories based on our finding that is unreasonable to require these areas to comply with the diesel requirements due to the territories' unique geographical, meteorological and economic factors, as well as other significant factors.  While these areas were exempted from the requirements, it does not preclude them from transitioning to lower sulfur diesel fuel.

Learn more about EPA's decisions to exempt the Mariana Islands, Guam and American Samoa.

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