Personal protective equipment for protection of the airways

• A respiratory protective equipment is meant to protect a person against hazardous substances present in the athmosphere where he/she should work under forms like solid or liquid aerosols or gas, vapours or steam.
• The user of a respiratory protective equipment must know the nature of the present risks (composition and concentration of the toxic substances) in the athmosphere in which he/she should work on one hand, and the performance level and limits of the respirator on the other hand. It’s important to take into consideration the time during which the protection must be ensured as well as the physiologic charge (breathing rhythm) of the user in order to select a respirator having the adapted autonomy.
• The Occupational Exposure Limit values are the levels of toxic contaminants to which an unprotected worker may be exposed during a given period without adverse health effects. Are distinguished the Long Term Exposure Limit (LTEL for exposure to an 8-hour period) and the Short Term Exposure Limit (STEL for exposure to a 15-minute interval).
• These values depend on national legislations.

Disposable particulate half-masks against aerosols :
• They are totally or mostly made in the filtering material itself.
• They can be made with or without a exhaltation valve.
• These protectors are covered by the European Standard EN149 : 2001.
• They are marked FFP1 (low filtering capacity), FFP2 (medium filtering capacity) or FFP3 (high filtering capacity). "SL" if they both protect against solid and liquid aerosols.
• They are marked "VO" when they protect against organic vapours and "GA" if they protect against acid gases.

Full-face and half-face masks with filtre cartridges :
• Full-face masks cover the forehead, nose, mouth and chin and have a ocular piece ; their caracteristics are described in the European standard EN136.
• Half-face masks cover the nose, mouth and chin and are discribed in the European standard EN140.
• To wear a face mask like a full-face or a half-face mask, it is necessary to make sure that the sealing surface is completely continuous to the face. Men must be correctly shaven and any interposition of hair, beard, or glasses temples must be avoided (otherwise the assigned protection factor will be reduced).
• The threaded filtre cartridges for the masks comply with the European standards EN141 and EN14387 (anti-gas and combined filtres) and EN143 (anti-aerosols) and are labelled with colour-codes according to the European standards and filtering classes : 1 = low capacity, 2 = medium capacity, 3 = high capacity.
• Never use the filtering masks in atmospheres where the Oxygen content is lower than 17 Vol.%.