On October 14, the Environmental Protection Agency announced plans to propose revisions to the nonhazardous secondary materials rule that sets definitions for biomass and other materials, under pressure from industry and members of Congress. The new rule will define which materials burned in combustion units are solid waste and which are fuels, and thus subject to far less stringent emissions standards. In an October 14 letter from EPA Administrator Lisa Jackson to Sen. Olympia Snowe (R-ME) the agency promised to review the rule, after receiving a letter ten days earlier from Snowe and ten other members of Congress asking for the rule to be clarified. EPA said it will unambiguously confirm that agricultural and forest-derived biomass, bagasse, other crop and tree residues, biomass crops, vines, orchard trees, hogged fuel (including wood pallets) sawdust, wood pellets, wood debris from forests, wood debris from urban areas, and if clean, cellulosic biofuels.