40 CFR § 426.20
Applicability; description of the sheet glass manufacturing subcategory
June 9, 2020
The provisions of this subpart are applicable to discharges of pollutants resulting from the process in which several mineral ingredients (sand, soda ash, limestone, dolomite, cullen and other ingredients) are mixed, melted in a furnace, and drawn vertically from a melting tank to form sheet glass.