Section 225.70  Ventilation

a)         The quantity of air reaching the last open crosscut in any set of entries must be greater than or equal to 9,000 cubic feet per minute; if diesel equipment is used, then the quantity of air reaching the last cross-cut must meet the standards of 62 Ill. Adm. Code 220.230(g)(3).

b)         In any working face where coal is being penetrated or loaded as a result of permissible explosives, the air sweeping the work face must be greater than or equal to 3,000 cubic feet per minute at all times persons are working at the face.