BOPF
Basic oxygen process furnace (BOPF) means any furnace with a refractory lining in which molten steel is produced by charging scrap metal, molten iron, and flux materials or alloy additions into a vessel and by introducing a high volume of oxygen-rich gas. Open hearth, blast, and reverberatory furnaces are not included in this definition.
Source
40 CFR § 60.141a
Scoping language
All terms in this subpart not defined below are given the same meaning as in the Clean Air Act as amended or in subpart A of this part.