                                 CODE OF VIRGINIA

 QUANTITY OF AIR (§ 45.2-836)

A. The quantity of air passing through the last open crosscut shall be at least
9,000 cubic feet per minute. However, the quantity of air reaching the last open
crosscut in a pillar-recovery section may be less than 9,000 cubic feet per
minute if at least 9,000 cubic feet of air per minute is being delivered to the
intake end of the pillar line.

B. The air current at a working face shall, under all conditions, have a
sufficient volume and velocity to readily dilute and carry away smoke from
blasting and any flammable or harmful gases and dust.

C. In a longwall or shortwall mining system:

   1. The quantity of air shall be at least 30,000 cubic feet per minute reaching
   the working face, unless otherwise approved by the Chief; and

   2. The velocity of air provided to control dust at designated locations on the
   longwall or shortwall face shall be maintained in accordance with the
   provisions of the mine ventilation plan approved by MSHA.

D. Ventilation shall be maintained during the installation or removal of
mechanized mining equipment.

HISTORY: Code 1950, §§ 45-4.1, 45-9, 45-12, 45-60.4, 45-74; 1954, c. 191;
1966, c. 594, §§ 45.1-5, 45.1-56; 1968, c. 310; 1976, c. 598; 1978, c. 120;
1984, c. 236; 1985, c. 448; 1987, c. 470; 1990, c. 963; 1993, c. 442; 1994, c.
28, § 45.1-161.219; 1996, c. 774; 2005, c. 3; 2021, Sp. Sess. I, c. 387.