The current tools and methods available to prevention officers must take into account the factors that can influence the breakthrough time and therefore the protection period offered by the gas filters.
The main factors are :
o The gas concentration
The higher the concentration, the shorter the breakthrough time. The competition (cross-contamination) between the different pollutants to be filtered must also be taken into account.
o The air flow to be filteredor the breathing rate
The higher they are, the lower the breakthrough time. For negative pressure masks, this requires the air flow breathed by eac hoperator to be evaluated (intensity of the work, mask position, breathing rate, facial hair, etc.). This evaluation is easier with powered air purifying respirators (PAPR) that have a predefined flow rate setting.
o The temperature
The higher the temperature, the shorter the life of the gas filter.
o The humidity
For organic gases, high humidity accelerates the breakthrough, while the opposite effect is observed for ammonia and hydrogen sulfide
Impacts can cause compression of the adsorbent material, modifying its compactness and potentially creating preferential paths (microcracks) which restrict its adsorbent capacity.
These factors often evolve and are difficult tomeasure on a daily basis. They make the theoretical evaluation work expensive and/or complex to perform on a daily basis, with sometimes significant uncertainties regarding the result compared to the actual conditions of use.
This theoretical work, although partially representative of actual conditions of use, is still necessary in order to pre-dimension the prevention device. The SatMETÆR is the ideal tool to complement the pre-dimensioning work with saturation measurements taken in the field on the gas filters before, during and after their use.
Make sure that your respiratory protective equipment is fully operational and bring confidence to your employees