National Emissions Standards for Hazardous Air Pollutants: Mineral Wool Production and Wool Fiberglass Manufacturing

The EPA is proposing amendments to the national emissions standards for hazardous air pollutants for Mineral Wool Production and Wool Fiberglass Manufacturing to address the results of the residual risk and technology review that the EPA is required to conduct by the Clean Air Act. The proposed Mineral Wool Production amendments include emissions limits for carbonyl sulfide, hydrogen fluoride and hydrochloric acid for cupolas; add combined collection and curing processes as new regulated sources; and include emissions limits for formaldehyde, phenol and methanol for combined collection and curing operations. Modifications to the testing and monitoring and related notification, recordkeeping and reporting requirements are also proposed. The proposed amendments for the Wool Fiberglass Manufacturing source category include emissions limits for chromium compounds, hydrogen fluoride, hydrochloric acid and particulate matter for glass- melting furnaces at major sources; revised emissions limits for formaldehyde, and the addition of emissions limits for phenol and methanol for bonded product lines at major sources; and modifications to testing and monitoring and related notification, recordkeeping and reporting requirements. These proposed rules only apply to major sources, but we plan to regulate wool fiberglass area sources in a future action. We are also proposing to revise provisions addressing periods of startup, shutdown and malfunction to ensure that the rules are consistent with a recent court decision.