The operator of a mine shall provide and maintain the necessary artificial means of capacity and power capable of supplying the required ventilation, and shall maintain a sufficient volume of air, not less per minute than one hundred fifty cubic feet for each person measured at the point in the mine where distribution to the various working sections begins and distributed to the working faces so as to expel or dilute and render harmless, explosive, poisonous, and noxious gases. The air shall be measured at the last entry break-through in each working section to see that a sufficient volume of air, not less than nine thousand cubic feet per minute, is being distributed at such point, provided that in gaseous mines the volume of air maintained for each person shall be not less than two hundred cubic feet per minute measured at the point in the mine where distribution to the various working sections begins.

No more than sixty-five workers shall be permitted to work on one continuous current of air or split of air except with the written consent of the chief of the division of mineral resources management, and in no case shall the number of workers exceed ninety.

Air in which workers work or travel in mines shall be improved when it contains less than nineteen and one-half per cent oxygen, or more than one-half of one per cent carbon dioxide, or is contaminated with noxious or poisonous gases. If the air immediately returning from a split that ventilates any group of active workings contains more than one per cent methane, as determined with a permissible flame safety lamp, by air analysis, or by other recognized means of accurate detection, the ventilation shall be improved. If the air immediately returning from such a split contains one and one-half per cent methane, the employees shall be withdrawn from the mine or the portion of the mine affected thereby, and all power shall be cut off from such mine or portion of the mine until such dangerous condition has been corrected. If the air immediately returning from such a split contains one and one-half per cent or more of methane, but not more than two per cent of methane, withdrawal of the employees from such mine or portion of the mine and shutting off all power from such mine or portion of the mine shall not be required if all of the following requirements are met:

(A) The volume of air provided and maintained in such split is equal to or in excess of eighteen thousand cubic feet of air per minute;

(B) Only permissible electric equipment is used;

(C) The air does not pass over trolley or other bare power wires;

(D) An official certified under this chapter and Chapters 1561., 1563., and 1565. of the Revised Code is continually testing the gas content of the air during the mining operations therein.

At working faces and other places where methane has accumulated and is likely to attain an explosive mixture, blasting shall not be done and the workers shall be removed from such working faces or places until such condition has been corrected.

When the methane content of air in face operations exceeds one per cent at any point twelve or more inches from the roof, face, or rib, as determined by a permissible methane detector, a permissible flame safety lamp, or analysis, such condition shall be corrected by improving the ventilation promptly. The electric face equipment at such point shall be turned off and not turned back on until the methane condition is corrected by improving the ventilation.

In gaseous mines, air that has passed through abandoned panel sections shall not be re-used to ventilate live workings. Mines that cannot comply with this requirement at once may continue to operate as at present for a reasonable length of time until future mine development and ventilation can be changed to permit compliance with this section.

No operator of a mine shall refuse or neglect to comply with this section.

Effective Date: 06-14-2000.