1. (a) Opacity limit. No person shall allow the discharge of any fumes, aerosol, mist, gas, smoke, vapor, particulate matter or any combination thereof exhibiting greater than 20% opacity. This requirement shall not apply to visible emissions exhibiting greater than 20% opacity emitted during short-term occurrences, which consist of not more than one six-minute period in any consecutive 60 minutes, not to exceed three such periods in any consecutive 24 hours, during which the average of any six-minute period shall not exceed 60% opacity.
2. (b) Alternate opacity limit. The 20% opacity limit required under 252:100-24-4 (a) may be increased for particulates only provided that the owner or operator demonstrates to the satisfaction of the Air Quality Council at public hearing that those requirements listed in 252:100-25-4 (a) through (c) have been met.

3. (c) Exceptions. Exceptions to the 20% opacity limit described in 252:100-24-4 (a) are provided as follows:

   1. (1) Visible emissions from loading-out (shipping) shall be no more than sixty-five percent (65%) opacity, and visible emissions from unloading (receiving) shall be no more than fifty-five percent (55%) opacity.
   2. (2) Emissions from pressurized vents or openings without control devices shall either be enclosed, exhausted through a control device, or shall be limited to no greater than ten percent (10%) opacity.
   3. (3) Emissions from non-pressurized vents or openings without control devices shall be limited to no greater than 10% opacity.

Added at 12 Ok Reg 353, eff 11-17-94 (emergency)

Added at 12 Ok Reg 1621, eff 7-1-95

Amended at 13 Ok Reg 815, eff 8-21-95 (emergency)

Amended at 13 Ok Reg 1951, eff 7-1-96

Amended at 16 Ok Reg 1370, eff 6-1-99

Amended at 25 Ok Reg 2223, eff 7-11-08