2005 Missouri Revised Statutes - § 293.120. — Air safety requirements.

293.120. Air in which men work or travel in mines shall be improved when:

(1) It contains less than nineteen and five-tenths percent oxygen;

(2) It contains more than one-hundredth percent carbon monoxide;

(3) It contains more than five-tenths percent carbon dioxide;

(4) It contains more than one percent methane; or

(5) Is contaminated with dust or with noxious or poisonous gases in excess of accepted limits as established by the director of the division of mine inspection.

(L. 1959 S.B. 188 § 13)