Not more than forty-five persons shall be permitted to work in the same air current and mines where ten or more persons are employed shall be provided with a fan or other artificial means to produce the ventilation, but no furnace shall be used where mines generate gases in dangerous guantities, and all stoppings between main intake and return airways hereafter built or replaced shall be substantially built of suitable masonry, or concrete which shall be approved by the inspector of the district.
Okla. Stat. tit. 45, § 517
Number working in same air current - Fans and furnaces - Stoppings between intake and return airways
R.L.1910, § 3972.
Official source: Oklahoma Legislature. Reproduced from public-domain Oklahoma statutes; confirm against the official source for the current text. Not legal advice.