35 Ill. Adm. Code 216.121
Fuel Combustion Emission Sources
Section 216
Section 216.121 Fuel
Combustion Emission Sources
A person must not cause or allow
the emission of carbon monoxide (CO) into the atmosphere from any fuel
combustion emission source with actual heat input greater than 2.9 MW (10
mmbtu/hr) to exceed 200 ppm, corrected to 50 percent excess air.