Due to the current pandemic, FFP2 masks must be worn for certain activities. According to the current state of knowledge, no FFP2 masks made of dissipative material are offered, only those made of insulating material. The projection of the largest area of the mask exceeds the maximum permissible surface in zone 1 according to TRGS 727 number 3.2.1 table 1a. When used in Zone 2, there is no area limitation, but experience has shown that no igniting discharges may occur.
In the case of an object made of an insulating material, consider whether a dangerous charge can be expected. This is the case when the mask is removed from a protective wrapping (“plastic bag”), but not when the mask is worn as intended (in contrast to activities that involve insulating aprons or similar).
The mask is worn directly on the body, it gets damp quite quickly, so that the surface resistance on the inside probably decreases quickly and the mask can be classified as conductive. This means that when wearing safety shoes with the required leakage resistance of 108 Ω, there is an earth contact of the mask.
Accordingly, FFP2 masks can be worn in potentially explosive areas for substances in explosion groups IIA and IIB in zones 1 and 2, provided that there are no strong charge-generating processes during the activities (this is not the case when carrying and manual processes) and there are no metallic internals on the surface of the mask (noseband embedded in the material is harmless).
The mask must be put on and taken off outside the potentially explosive areas. Repacking should NOT take place in the Ex area and to use non-static plastic bags.
Note:
If the workplace limit values are exceeded or if there is an explosive atmosphere, there is a health risk since FFP2 masks do not protect against gases and vapors or in the event of a lack of oxygen!
All possible ignition sources shall be considered in case of hazardous area compliance – FFP2 masks are no exceptions.
Keep up good work!
Arpad