Section 296-818-30010. Blast cleaning enclosures.

You must:

• Install adequate ventilation systems in blast cleaning enclosures that are able to do all of the following:

– Control concentrations of airborne contaminants below the permissible exposure limits that apply

– Provide a continuous inward flow of air at all openings in the enclosure during blasting operations

– Minimize the escape of dust into adjacent work areas

– Maintain visibility in blast cleaning rooms and cabinets

– Rapidly clear dust from the air after blasting stops

– Discharge exhaust so contaminated air does not do either of the following:

■ Present a health hazard to any worker; or

■ Reenter buildings in harmful amounts

• Make sure ventilation systems are designed and operated so employees are not exposed to excessive air velocities

• Make sure make-up air systems do not interfere with the effectiveness of the exhaust system, and are designed to do both of the following:

– Replace exhausted air in ample quantities

– Temper make-up (supply) air when necessary

• Do both of the following before opening the blast cleaning enclosure:

– Turn the blast off

– Run the exhaust system for a sufficient period of time to clear the air of dust particles

• Follow the requirements in Table-2, Blast Cleaning Enclosures.

Table-2: Blast Cleaning Enclosures

References:	For more information on:
	• Air velocities, refer to the following:
	– The latest edition of Recommended Industrial Ventilation Guidelines (ACGIH)
	– NIOSH 1976 Industrial Ventilation
	• Exit routes, go to the Safety and health core rules, WAC 296-800-310.

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060. WSR 06-12-074, § 296-818-30010, filed 6/6/06, effective 9/1/06.]

RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060. WSR 06-12-074, § 296-818-30010, filed 6/6/06, effective 9/1/06.

Rules

296-800-310,