EPA Proposes Change To Air Toxics Rule

The Bush Administration on Dec. 21, 2006, proposed a controversial change in the way carcinogens and other hazardous air pollutants are regulated. EPA says the modification, which is backed by industry groups including the American Chemistry Council, would encourage facilities to reduce their emissions of these 188 toxic air pollutants (C&EN, April 24, 2006, page 32). Environmental groups say the proposal could allow companies that have already curbed their emissions of air toxics to boost their releases. A year ago, EPA officials from eight of the agency's 10 regional offices voiced similar concerns about the proposal as it was being drafted. The proposal affects how industrial plants are classified into one of two categories for regulation of hazardous air pollutants. One category, called a major source, includes any facility that can potentially release more than 10 tons per year of any one air toxic or 25 tons per year of any combination of these substances. Major sources must install maximum achievable control technology to reduce releases of hazardous air pollutants and are tightly regulated. Facilities emitting hazardous air pollutants below these limits are considered "area sources" and are less stringently regulated. The proposal would allow any major source to be reclassified as a less regulated area source if it reduces its emissions below the 10-ton-per-year and 25-ton-per-year thresholds. Such a reclassification is prohibited under present EPA policy.