Ohio Revised Code Title XV. Conservation of Natural Resources § 1563.02

(A) A mine in which methane has been ignited;

(B) A mine in which methane has been detected in any of the open workings thereof by a permissible flame safety lamp;

(C) A mine in which one fourth of one per cent or more of methane has been found in a sample of air taken in any of the open workings thereof upon analysis thereof by the mine laboratory provided for by section 1561.27 of the Revised Code. If such sample of air contains less than one half of one per cent of methane and if no other sample of air, taken in any of the open workings of such mine within twenty-four hours of the time such first-mentioned sample was taken, is, upon analysis by said laboratory, found to contain one fourth of one per cent or more of methane, such mine is not a gaseous mine unless a sample of air thereafter taken in any of the open workings of such mine and prior to ten days after the date upon which such first-mentioned sample was analyzed is, upon analysis by said laboratory, found to contain one fourth of one per cent or more of methane.