Okla. Stat. tit. 45 § 441
The use of diesel engines equipped for detoxification in accordance with rules and regulations promulgated by the U.S. Bureau of mines may be used in lead, zinc, and other metal mines in this state. Provided, the use of such engine or engines in any such mine is first found to be safe for the miners who work in said mine, by the assistant mine inspector, and such finding is approved by the Chief Mine Inspector and provided further, that the diesel engine or engines and the safety equipment thereon to be used in any such mine shall also have been approved for use in such mine, by the assistant mine inspector, and such finding is approved by the Chief Mine Inspector. The assistant mine inspector and the Chief Mine Inspector, in issuing any such approval, shall follow the rules and regulations and recommendations of the U.S. Bureau of mines. The assistant mine inspector shall make periodical inspections to determine whether such engines in such mines are emitting fumes which make it unsafe for such engines to be used. The assistant mine inspector or the Chief Mine Inspector shall have the authority to order that conditions be remedied, and to suspend the use of such engines in any mine, or to order the discontinuance altogether of such engines in any such mine. Such orders shall be enforced as other orders of such officers are enforced.
Okla. Stat. tit. 45, § 441