Talk:FFP standards

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Protection against viruses?

Why does the article claim that the mask protects against viruses, without mentioning diameters of virions and the pore size of the masks?

These masks do not have a "pore size". This is a misunderstanding of how they work. They have a mesh of fibres that get electrically charged, and small particles get stuck to the surface of these electrostatically charged fibres (usually polypropylene). The difference between the different classes of EN 149 mask (FFP1, FFP2, FFP3) is not any pore size, but just the number of layers of melt-blown polypropylene cloth that is used in the respective mask. You might have a single sheet of melt-blown polypropylene cloth in an FFP1 mask, three layers in an FFP2 mask and 5 or 7 layers in an FFP3 mask. The standard does not prescribe how the mask is made, it just describes a list of performance tests that they have to pass. Jomsborg (talk) 10:40, 28 November 2020 (UTC)[reply]

I find that claim awkward, even more so as in high safety labs people may wear full body suits, so there is a logical discrepancy here if they wear full body protection yet the article here on wikipedia insinuates that FFP2 would protect against coronaviruses as-is. Even more so as a percentage value is given, so if that is above 0%, why is "protection" assumed if it is higher than 0%? 2A02:8388:1641:8380:3AD5:47FF:FE18:CC7F (talk) 19:42, 26 May 2020 (UTC)[reply]

The EN 149 standard does not talk about viruses (or other pathogens) at all. Viruses do not travel through air alone, they are always a tiny fraction of the mass of a much larger liquid particle that they travel in. The purpose of the mask is to reduce the number of liquid particles that the wearer inhales. That will indirectly also reduce the number of viruses inhaled, in particular viruses sitting on particles that might be able to travel deep into the respiratory system. EN 149 specifies a series of tests for filter masks using saline aerosol. I am not aware of any filter mask standard that tests anything specific to virus particles, for many reasons (viruses are difficult to produce and count in precise quantities). The mask standards all for test aerosol particles instead, i.e. a mist of liquid droplets with a given statistical distribution of diameters. The filtration percentage refers to that for aerosol particle diameters in the worst case range, i.e. an FFP2 filter will hold back 94% of the aerosol particles with the _worst_ diameters, it generally performs much _better_ for larger _and_ smaller particles (smaller particles get much more easily stuck on the charged polypropylene fibres). Jomsborg (talk) 10:40, 28 November 2020 (UTC)[reply]

Diameter

Could the diameter for filter size be mentioned in the table? E. g. to see the nanosize range and whether these masks make a difference, depending on the size. 2A02:8388:1641:8380:B9AB:76FC:25B:61AE (talk) 20:46, 14 July 2020 (UTC)[reply]

FFP4

This page doesn't contain FFP4. They sell FFP4 masks. Are there even more classes?— Preceding unsigned comment added by Ilkant (talkcontribs) 09:51, 8 August 2021 (UTC)[reply]

Hello Ilkant, EN 149 is the European norm that defines the standards on FFP masks. There is no definition for a FFP4 standard, and therefore not mentioned in this article. Someone selling "FFP4 masks" is not an honourable merchant.– NJD-DE (talk) 14:40, 8 August 2021 (UTC)[reply]

How were the filtration percentages and allowed leak rates decided?

Apokrif (talk) 23:08, 18 September 2021 (UTC)[reply]