35 Ill. Adm. Code 214.401
Glass Melting and Heat Treating
Section 214
Section 214.401 Glass
Melting and Heat Treating
Section 214.301 shall not apply
to:
a) Glass melting furnaces in the Chicago or St. Louis (Illinois)
major metropolitan areas.
b) Glass heat treating with sulfur dioxide in the St. Louis
(Illinois) major metropolitan area.