Respiratory protection, The Half mask WILLSON PREMIER large is designed to work when external concentration allows it.
The type of protection depends on the cartridges connected, gases, particules or combined.
The threshold is depending on a theoretical calculation, based on the facial leakage and the efficiency of the adapted canister. The APF is evaluated from 12 to 50. It allows the use of the Half mask from an external concentration between 12 time to 50 time the Occupational Exposure Limit.
The half mask WILLSON PREMIER large can be used only with certified T SERIES cartridges (following the standard EN 141 , EN 143)
The oxygene concentration has to be superior to 17%