The Clean Air Act requires many of the largest emitters of toxic air pollutants like arsenic and mercury to reduce their emissions by the maximum degree possible. In January 2007, the EPA proposed a rule change that would allow polluters to sidestep the requirement if they release less than 10 tons per year of a single pollutant or less than 25 tons per year of combined pollutants. Environmentalists and some EPA regional staff criticized the proposed rule, saying it would enable oil refineries, large waste incinerators, power plants, and others to significantly increase their toxic emissions, placing children and families in neighboring communities at risk.

During consideration of H.R. 2643, the Interior-Environment appropriations bill, Representative Eddie Bernice Johnson (D-TX) introduced an amendment to deny funds for implementing the proposed rule change. On June 26, 2007, the House approved the amendment by a 252-178 vote (House roll call vote 556). YES is the pro-environment vote.