MTBE, or methyl tertiary-butyl ether, a gasoline additive that is also a carcinogenic pollutant, is prone to leaking into groundwater from underground storage tanks. This has saddled communities across the country with billions of dollars in clean-up costs. Many of these communities are trying to hold MTBE manufacturers responsible for the damage their products have caused.

The Bush Administration and its congressional allies have placed a special priority on shielding MTBE manufacturers from liability. During consideration of H.R. 6, the House energy bill, Representative Lois Capps (D-CA) offered an amendment to remove this liability shield, arguing that it constituted an unfunded mandate on states and local taxpayers.

On April 21, 2005, House Amendment 370 was rejected by a 213-219 vote (House roll call vote 129). YES is the pro-environment vote. The liability-shield provision was later removed in House-Senate conference and was not part of the final energy bill.