EPA plans to clamp down on hazardous air pollutants emitted from boilers and process heaters, which generate heat or electricity. These devices are common at large industrial facilities such as chemical manufacturing plants and in commercial settings such as universities and hotels. An April 30 proposal from EPA would reduce emissions of mercury, lead, cadmium, dioxins, furans, formaldehyde, and hydrochloric acid from boilers and process heaters. The proposal would affect boilers and process heaters that burn biomass, oil, coal, or nonhazardous waste such as used oil. Two industry groups, the American Chemistry Council and the Society of Chemical Manufacturers & Affiliates, applauded EPA for excluding gas-fired boilers and process heaters from proposed requirements for pollution scrubbers. Large industrial boilers and process heaters together are the second largest source of mercury emissions in the U.S., after coal-fired power plants, releasing 16,000 lb of the metal yearly. EPA is under court order to finalize the proposal by Dec. 16.