EN 149 explained
This European Standard specifies the minimum requirements for filtering half masks used as respiratory protective devices, specifically against particles, and the required laboratory and practical performance tests to assess masks’ compliance. Half masks used for escape purposes are excluded from the scope of this standard.
A filtering half mask is one in which the facepiece consists entirely or substantially of filter material or comprises a facepiece in which the main filter(s) form an inseparable part of the device.
Under the preceding EN149:1991 standard, the classifications were FFP1S, FFP2S, FFP2SL, FFP3S and FFP3SL. EN149:2001 classified half masks into three types according to their filtering capacities (e.g., FFP1, FFP2, and FFP3). Respirators that meet the requirements of EN149:2001 are designed to protect against solids, water-based aerosols, and oil-based aerosols.
EN149:2001 differs from EN149:1991 in that it is mandatory for all products tested in accordance with EN149:2001 to provide protection against solid and liquid aerosols whereas EN149:1991 allows for the testing of respirators against solid aerosols only. On 1 August 1 2010, an amendment to EN 149.2001 standard entered into force concerning the reusability of masks’ dust filters, indicated by “R”, reusable, and “NR”, non-reusable, and tagged as EN 149:2001+A1:2009.
EN 149 defines the following classes of filtering half masks (i.e., respirators that are entirely or substantially constructed of filtering material):
Class APF (Assigned Protection factor) Filter penetration limit (at 95 L/min air flow) Inward leakage
To confirm: an FFP3 respirator mask would filter out at least 98% of the airborne respirable particles, whereas an FFP1 respirator mask would filter out at least 80% of the respirable particles. FFP3 respirator masks are, therefore, the most efficient in filtering out fine particles including viruses, mold spores, and asbestos.