{"data":{"id":"us/40-cfr-60.291","jurisdiction":"us","citation":"40 CFR 60.291","heading":"Definitions.","body":"As used in this subpart, all terms not defined herein shall have the meaning given them in the Act and in subpart A of this part, unless otherwise required by the context.\nAll-electric melter means a glass melting furnace in which all the heat required for melting is provided by electric current from electrodes submerged in the molten glass, although some fossil fuel may be charged to the furnace as raw material only.\nBorosilicate recipe means glass product composition of the following approximate ranges of weight proportions: 60 to 80 percent silicon dioxide, 4 to 10 percent total R2O (e.g., Na2O and K2O), 5 to 35 percent boric oxides, and 0 to 13 percent other oxides.\nContainer glass means glass made of soda-lime recipe, clear or colored, which is pressed and/or blown into bottles, jars, ampoules, and other products listed in Standard Industrial Classification 3221 (SIC 3221).\nExperimental furnace means a glass melting furnace with the sole purpose of operating to evaluate glass melting processes, technologies, or glass products. An experimental furnace does not produce glass that is sold (except for further research and development purposes) or that is used as a raw material for nonexperimental furnaces.\nFlat glass means glass made of soda-lime recipe and produced into continuous flat sheets and other products listed in SIC 3211.\nFlow channels means appendages used for conditioning and distributing molten glass to forming apparatuses and are a permanently separate source of emissions such that no mixing of emissions occurs with emissions from the melter cooling system prior to their being vented to the atmosphere.\nGlass melting furnace means a unit comprising a refractory vessel in which raw materials are charged, melted at high temperature, refined, and conditioned to produce molten glass. The unit includes foundations, superstructure and retaining walls, raw material charger systems, heat exchangers, melter cooling system, exhaust system, refractory brick work, fuel supply and electrical boosting equipment, integral control systems and instrumentation, and appendages for conditioning and distributing molten glass to forming apparatuses. The forming apparatuses, including the float bath used in flat glass manufacturing and flow channels in wool fiberglass and textile fiberglass manufacturing, are not considered part of the glass melting furnace.\nGlass produced means the weight of the glass pulled from the glass melting furnace.\nHand glass melting furnace means a glass melting furnace where the molten glass is removed from the furnace by a glassworker using a blowpipe or a pontil.\nLead recipe means glass product composition of the following ranges of weight proportions: 50 to 60 percent silicon dioxide, 18 to 35 percent lead oxides, 5 to 20 percent total R2O (e.g., Na2O and K2O), 0 to 8 percent total R2O3 (e.g., Al2O3), 0 to 15 percent total RO (e.g., CaO, MgO), other than lead oxide, and 5 to 10 percent other oxides.\nPressed and blown glass means glass which is pressed, blown, or both, including textile fiberglass, noncontinuous flat glass, noncontainer glass, and other products listed in SIC 3229. It is separated into:\n(1) Glass of borosilicate recipe.\n(2) Glass of soda-lime and lead recipes.\n(3) Glass of opal, fluoride, and other recipes.\nRebricking means cold replacement of damaged or worn refractory parts of the glass melting furnace. Rebricking includes replacement of the refractories comprising the bottom, sidewalls, or roof of the melting vessel; replacement of refractory work in the heat exchanger; replacement of refractory portions of the glass conditioning and distribution system.\nSoda-lime recipe means glass product composition of the following ranges of weight proportions: 60 to 75 percent silicon dioxide, 10 to 17 percent total R2O (e.g., Na2O and K2O), 8 to 20 percent total RO but not to include any PbO (e.g., CaO, and MgO), 0 to 8 percent total R2O3 (e.g., Al2O3), and 1 to 5 percent other oxides.\nTextile fiberglass means fibrous glass in the form of continuous strands having uniform thickness.\nWith modified-processes means using any technique designed to minimize emissions without the use of add-on pollution controls.\nWool fiberglass means fibrous glass of random texture, including fiberglass insulation, and other products listed in SIC 3296.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 60—STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES","Subpart CC—Standards of Performance for Glass Manufacturing Plants"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"d66401036a3f3f054381481f3bc2300225279ca6fe15c1b463a45139a80e539e","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-60.290","next":"us/40-cfr-60.292"},"notice":"GroundRules: Original legal text. Not legal advice."}