Schutzwirkung von chirurgischen Masken und FFP2-Masken vor feinen und ultrafeinen Aerosolen

Aerosols are a mixture of solid or liquid particles with a size between 1 nm and several 100 µm in a gas or gas mixture. Not only healthcare professionals can be affected by infectious aerosols. Noninfectious aerosols, e.g., fungal spores, nanoparticles, dusts and chemical vapors, can be hazardous to many occupational groups. Using masks is an effective measure to protect against aerosols. This study aimed to demonstrate the importance and limitations of wearing surgical and FFP2 masks for protection against fine and ultrafine aerosols in a realistic setting.

Aerosols with di(2-ethylhexyl) sebacate (DEHS) and aqueous aerosols were generated in a laboratory room with a floor area of 27 m² and a volume of approximately 80 m³. The aerosols generated were quantified with a spectrometer in the range between 5.6 and 560 nm. Installed phantom heads at the aerosol generator (emitter) and spectrometer (receiver) could be equipped with masks and the distance between them could be changed.

For DEHS aerosols (distances phantom heads emitter to receiver 150–300 cm) and aqueous aerosols (distance 100 cm), a very significant (p < 0.001) reduction in aerosol exposure was observed when a surgical or FFP2 mask was attached to the emitter. If a mask was only attached to the receiver, a well-fitting FFP2 mask taped to the phantom head provided the significantly (p < 0.001) best protection against aerosols, significantly ahead of the non-taped FFP2 and surgical masks.

Surgical and FFP2 masks provide good external protection; however, only masks that fit really well and tightly offer really good self-protection. Surgical masks are only suitable for self-protection to a very limited extent.