• Greenhouse gases. An amendment sponsored by Rep. Ted Poe (R) of Texas would prohibit EPA use of funds to implement or enforce any statutory or regulatory requirement pertaining to emissions of greenhouse gases.

• Fossil-fuel 'waste.' An amendment sponsored by Rep. David McKinley (R) of West Virginia would prohibit the EPA from using its funds to develop or enforce any regulation that identifies or lists wastes produced by the burning of fossil fuels – such as ash or slag – as hazardous waste. The EPA currently does not define these wastes as hazardous, though some are regulated when used in landfills or to fill mines.

• Farm dust. An amendment sponsored by Rep. Kristi Noem (R) of South Dakota would prohibit funds from being used to modify national air-quality standards to include coarse particulate matter under the Clean Air Act. Some farmers are worried that the dust kicked up by tractors could come under EPA regulations if coarse particulate matter came under national air-quality standards.

• Cement-plant emissions. An amendment proposed by Rep. John Carter (R) of Texas would prohibit any federal funds from being used to implement, administer, or enforce the EPA's new clean-air rule to regulate cement-plant emissions. EPA is set to soon begin requiring cuts in hazardous emissions of nearly one-third, or about 90 tons, annually nationwide and cut airborne particulate matter by 5,200 tons, or one-quarter overall.