3.H: Missouri

Missouri has one conventional gasoline formulation. In addition, the state adopts, on an “opt-in” basis, federal reformulated gasoline (RFG) for use in areas of the St. Louis metro area inside Missouri’s state borders. This area is defined as St. Louis, Jefferson, St. Charles and Franklin counties.

Fuel quality regulation is the responsibility of the state’s Department of Agriculture. Additionally, the federal Environmental Protection Agency (EPA) participates in the enforcement of RFG quality in the state.

Due to the state’s E10 blend mandate, all gasoline in the state is oxygenated, save for a handful of special-purpose carve-outs (i.e. premium-grade automotive gasoline, aviation fuel). Consistent with the EPA’s E15 partial waiver, the state allows a 1-psi (6.9 kPa) waiver fo