§ 95.105 VISIBLE EMISSIONS.
   It is unlawful for any person to discharge into the atmosphere or cause to be so discharged from any combustion or process equipment or device, vehicle, incinerator, or open fire whatsoever any air contaminant for a period aggregating more than five minutes in any one hour which is:
   (A)   As dark or darker in shade as that designated as No. 2 on Ringlemann Chart, as published by the United States Bureau of Mines; and
   (B)   Of an opacity as to obscure an observer’s view to a degree equal to or greater than does smoke described in division (A) above.
(Prior Code, § 102.105)