Reformulated gasoline is gasoline that has been blended in order to allow it to burn more cleanly and, therefore, emit fewer smog forming and toxic pollutants into the atmosphere. Reformulated gasoline produces between 5 and 17 percent less pollution than conventional gasoline. Reformulated gasoline is created by using smaller amounts of benzene than in conventional gases.
A reformulated gasoline program was mandated by the US Congress in the 1990 Clean Air Act amendments. Since 1995, the program has been rolling out a reformulated gasoline option at gasoline stations across the United States. In cities with high smog levels, providing a reformulated gasoline option is mandatory, while in other cities it is optional. Approximately 30 percent of the gasoline currently sold in the United States is reformulated.