Filters

There are 2 types of filter connectors:

• Proprietary filter connection: filter and mask must be from the same brand.
• With standard thread connection: EN 148-1 standard thread connection: filter and mask may be from a different brand.

There are 3 sorts of filters associated with these 2 types of connectors:

Dust filters: These filters are used for work activities that produce dust, mist or fumes. The action of a filter can be compared to a sieve. The finer the sieve, the better the filtering. The disadvantage of a very good filter is that the holes through which the user must breathe are smaller. The user must put in more effort to breathe. In other words, breathing resistance is greater with a fine filter when compared to a coarse filter. Furthermore, dust masks work on the principle of mechanical filtration, which means that when a filter becomes saturated, breathing becomes even more difficult. If the user perceives this, the filter must be replaced immediately.

Gas filters: These filters are used as protection against gases and vapours. The impurities can be blocked in 2 ways:

• Absorption: Here, the gases and vapours are deposited on the active carbon without a chemical reaction taking place.
• Chemical absorption: Thanks to the impregnated charcoal, a chemical reaction occurs between the gas or vapour and the product that has been used for impregnation

Upon saturation, the user will notice this by smell or taste. The filter must then be replaced as soon as possible This means that these gas filters may not be used if the product has no smell or taste. The condition for this is that the critical concentration is still below the threshold.

Combination filters: These are filters that provide combined protection against gas and/or dust; the filter layout and colour code remain the same. Should there be any symptoms of saturation of one of either of the two types of filter (dust or gas), it is then necessary to replace the combination filter immediately.