Note: following this Position Paper is National PSR's 1996
Resolution on MMT in the United States Gasoline Supply
Lead, an anti-knock additive, was finally phased out of use in non-aviation gasoline in 1995. Yet, that same year, another metal with potentially damaging health effects was cleared for addition to gasoline for the same purpose. In 1995, the EPA was forced by a federal judge to grant a waiver to the Ethyl Corporation allowing production and sale of methylcyclopentadienyl manganese tricarbonyl (MMT). Both the EPA and many health experts have serious concerns about the use of this compound in gasoline. MMT breaks down quickly on exposure to sunlight or in the car engine into compounds of the metal manganese.