"Smokeless flare" means a combustion unit and the stack to which it is affixed in which organic material achieves combustion by burning in the atmosphere such that the smoke or other particulate matter emitted to the atmosphere from such combustion does not have an appearance density or shade darker that No. 1 of the Ringlemann Chart.
Ill. Admin. Code tit. 35, § 211.6050
Added at 17 Ill. Reg. 16504, effective September 27, 1993