Okla. Stat. tit. 45 § 516
The operator of every coal or other mine, whether shaft, slope or drift shall provide and hereafter maintain ample means of ventilation affording not less than one hundred fifty (150) cubic feet of air per minute, for each and every person employed therein, and seven hundred fifty (750) cubic feet of air per minute for every animal employed therein; but, in a mine where fire damp has been detected, the minimum shall be two hundred (200) cubic feet per minute for each person employed therein, and as much more in either case as one or more of the mine inspectors may deem requisite, and the ventilation shall be conducted through the main cross entries and all other working places, so as to dilute and render harmless and expel therefrom the noxious and poisonous gases, and all working places shall be kept clear of standing gases.
Okla. Stat. tit. 45, § 516