(1) The employer shall assure that dry chemical agents are compatible with any foams or wetting agents with which they are used.
(2) The employer may not mix together dry chemical extinguishing agents of different compositions. The employer shall assure that dry chemical systems are refilled with the chemical stated on the approval nameplate or an equivalent compatible material.
(3) When dry chemical discharge may obscure vision, the employer must provide a predischarge employee alarm which will give employees time to safely exit from the discharge area prior to system discharge.
Your predischarge employee alarm systems must:
• Provide enough warning to allow employees to safely escape from the workplace or the immediate work area or both.
• Be capable of being perceived above ambient noise or light levels by all employees in the affected portions of the workplace before system discharge.
• Be distinctive and recognizable as a signal to evacuate the work area.
• Be kept in operating condition except when undergoing repairs or maintenance.
You must explain to each employee how to report emergencies in your workplace. Methods of reporting emergencies include manual pull box alarms, public address systems, radio, or telephones. Post emergency telephone numbers near telephones, or employee notice boards, or other conspicuous locations if you use telephones to report emergencies.
If you use a communication system that also serves as an employee alarm system, all emergency messages must have priority over all nonemergency messages.
(4) The employer shall sample the dry chemical supply of all but stored pressure systems at least annually to assure that the dry chemical supply is free of moisture which may cause the supply to cake or form lumps.
(5) The employer shall assure that the rate of application of dry chemicals is such that the designed concentration of the system will be reached within thirty seconds of initial discharge.
[Statutory Authority: RCW 49.17.010
, [49.17].040, and [49.17].050. WSR 01-11-038, § 296-24-62203, filed 5/9/01, effective 9/1/01. Statutory Authority: RCW 49.17.040
and 49.17.050. WSR 82-02-003 (Order 81-32), § 296-24-62203, filed 12/24/81.]