Okla. Stat. tit. 45, § 45-441: Use of engines equipped for detoxification permitted -

Approval of use - Inspections - Suspension or discontinuance of use.

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.