Not More Than Seventy-five Persons Employed on One Split

Section 509. Not More Than Seventy-five Persons Employed on One Split.--Every mine employing more than seventy-five persons shall be divided into two or more districts. Each district shall be provided with a separate split of pure air and the ventilation shall be so arranged that not more than seventy-five persons shall be employed at the same time in any one current or split of air.