PDFWAC 296-835-11015

Take additional precautions if you recirculate ventilation system exhaust air into the workplace.

IMPORTANT:
This section applies if exhaust air from dipping or coating operations that use flammable liquids, or liquids with flashpoints greater than 199.4°F (93°C) is recirculated back into the work environment.
(1) You must only recirculate air that contains no substance at a concentration that could pose a health or safety hazard to employees.
(2) You must make sure any exhaust system that recirculates air into the workplace:
(a) Passes the air through a device that removes contaminants;
(b) Sounds an alarm and automatically shuts down the dip tank operation, if the vapor concentration of any substance in the exhaust air exceeds twenty-five percent of its LFL;
(c) Monitors the concentration of vapor from flammable liquids or liquids with flashpoints greater than 199.4°F (93°C) with approved equipment.
Note:
1. The LFL concentration in the air must be determined after the air passes through the air-cleaning device and before the air reenters the workspace.
 
2. Most substances will pose a health hazard at a concentration far below twenty-five percent of its LFL.
[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 17-18-075, § 296-835-11015, filed 9/5/17, effective 10/6/17. Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060 and 29 C.F.R. 1910 Subpart Z. WSR 14-07-086, § 296-835-11015, filed 3/18/14, effective 5/1/14. Statutory Authority: RCW 49.17.010, [49.17].040, and [49.17].050. WSR 02-15-102, § 296-835-11015, filed 7/17/02, effective 10/1/02.]