Powered respirators

Powered respirators

Use of respirators

 Before deciding to use respirators it must be considered whether a given air pollution by hazardous substances can be avoided, eg by use of less hazardous substances or air ventilation could bring pollution levels below the limit. Use of respirators must always be the last option. 

Respiratory protection must be used when breathing air is contaminated or suspected of being contaminated with particles, gases, vapors or fumes in concentrations above the limit. Respiratory protection must also be used if ambient concentrations of oxygen is below 17 volume percent. 
Users of breathing apparatus must, before commencing work, have thorough theoretical and practical instruction in the use and maintenance. 
 

Protection Factor 

Respiratory protection must be used from work start and throughout the period of staying in the contaminated area. Even a short stay without the use of respiratory protective equipment will significantly reduce the expected protection. For each  class of respirators is declared a probable protective factor at 100% use, where protection factor indicates how many times the air inside the mask is cleaner than the surrounding air. As soon as the time of use for the respiratory protective equipment drops, so will the protection factor but at even higher pace. At only 80% time of use there is actually almost no difference in using a dust mask or a full face mask. The protection factor would be almost identical. 
3 hour rule 
Use of respirators are burdensome for the body. Therefore the time of use is limited for certain types. Filtering respirators, where the user himself must breathe through a filter, may be used only for 3 hours a day. If the work extends over three hours, then from the start the user must wear respiratory protection with turbo unit (fan) or air-supplied respirator. 
 

Relevant standards

EN 136: Full face masks 
EN 137: Self contained breathing apparatus 
EN 138: Specification for fresh air hose breathing apparatus for use with full face mask, half mask or mouthpiece assembly
EN 14594: Continuous flow compressed air line breathing apparatus. Requirements, testing, marking (full face and half mask, HD hood and face shield, hood for sandblasting, LD hood and face shield) (prev. EN 139, 270, 271 and 1835) 
EN 140: Half masks and quarter masks
EN 14387: Gas and combined filters, AX gas and combined filters against low boiling organic compounds (pre EN 141 and 371) 
EN 143: Particle filters 
EN 149: Filtering half masks to protect against particles - Disposable Masks (2001) 
EN 401: Chemical oxygen (KO2) escape apparatus
EN 403: Filtering devices with hood for escape from fire
EN 405: Valved filtering half masks to protect against gases or gases and particles
EN 1146: Evacuation, Self-contained open-circuit compressed air breathing apparatus incorporating a hood
EN 12941: Powered filtering devices incorporating a helmet or a hood
EN 12942: Power assisted filtering devices incorporating full face masks, half masks or quarter masks
TM14/7.25: Ai r supplied hoo d/face shield 
 

Selection of respirators 

It is important to choose the correct respirator and the best product for the job. After taking account of both legal requirements, protection factor, three-hour rule and user comfort, so the choice is difficult. Therefore, you should contact the ICM to get the proper guidance. This makes the choice much easier.