The use of natural gas or liquid propane gas used in an after-burner.

OSHA interpretation letter from 1995 clarifying that the Process Safety Management standard, 29 CFR 1910.119, applies to processes involving listed chemicals at or above threshold quantities or 10,000 pounds or more of a flammable liquid or gas, with an exception for hydrocarbon fuels not part of a covered process. It also states that OSHA regulations address worker protection and do not cover…