Abrasive. A solid granular substance used in abrasive blasting operations.

Abrasive blasting. The forcible application of an abrasive to a surface using either:

(a) Pneumatic or hydraulic pressure; or

(b) Centrifugal force.

Abrasive-blasting respirator. A supplied air or a continuous flow respirator constructed with a shroud that covers and protects the head, neck, and shoulders.

Automatic blast cleaning systems. A unit that has a blast cleaning chamber which usually has both of the following to provide a timed cleaning cycle:

(a) An automatic timer; and

(b) An automatic shutoff control.

Baffles. Partial enclosures in and around the emission sources which improve or enhance airflow at the hood.

Blast cleaning barrel. A complete enclosure that rotates on an axis or an internal tread to tumble parts in order to expose various surfaces of the parts to an automatic blast spray.

Blast cleaning room. An enclosed room where blasting operations are performed by an operator who works from inside the room using a blasting nozzle to direct the flow of abrasive material.

Blasting cabinet. An enclosure where the operator stands outside using a blasting nozzle through an opening, or openings in the enclosure.

Dust collector. A device in an exhaust ventilation system used to remove dust from air.

Exhaust ventilation system. A system that removes contaminated air using the following:

(a) Enclosure or hood;

(b) Duct work;

(c) Dust collecting equipment;

(d) Exhauster; and

(e) Discharge stack.

Local exhaust ventilation. The mechanical removal of contaminated air from the point where the contaminant is being generated or liberated.

Make-up air systems. A ventilation system that controls the volume of outdoor air supplied to a building to replace air being exhausted.

Rotary blast cleaning table. An enclosure where the pieces to be cleaned are placed on a rotating table and passed automatically through a series of blast sprays.

Tempered make-up air. Air which has been conditioned by changing its heat content to get a specific desired temperature.

Ventilation. The provision, circulation or exhausting of air into or from an area or space.