Based on the standard DIN EN 149 (1) for particle filtering half masks, three tests that were significant to assess the protective effect were carried out in triplicate on 16 different, randomly selected typical market products (Table 9). N95 (mask N), which has been tested in accordance with NIOSH and recommended in the CDC guidelines (20) for the prevention of infections in tuberculosis (TB), is the only product approved as a respiratory protective device by an independent testing agency.
The previously mentioned "Mask N" is the high-risk mask from DACH Schutzbekleidung GmbH & Co. KG.
Four products meet the requirements for breathing apparatus according to DIN EN 149; Of these, three have a protective effect corresponding to the FFP1 type (maximum total leakage 22%) and one (mask N) even corresponds to the type FFP3 with 2% maximum permissible total leakage.
The total leakage of the high-risk mask (mask N) meets the requirements of the highest protection level FFP3 according to DIN EN 149. The total leakage is decisive for choosing the correct mask.
The use of more penetrating paraffin oil mist as a liquid aerosol was not considered in the case of viruses because of the different properties of oily compared to aqueous or water-based aerosols.
The DIN EN 149 standard prescribes an oil test. This test is not relevant for the NIOSH standard N95. As a result, a mask certified according to DIN EN 149 has a greater breathing resistance than a mask certified according to N95. The mask certified according to N95 is more suitable for protection against viruses and bacteria.
Mask N has a total leakage rate of an FFP3 mask and a lower breathing resistance than an FFP1 mask.