ROSSINI 2025

4 37 STANDARDS AND CERTI FICATIONS To determine the choice of a filter, you need to know the TLV value, the NOMINAL PROTECTION FACTOR OF THE PROTECTOR, the REQUIRED PROTECTION FACTOR and the TOXICITY OF THE CONTAMINANT. TLV: is the characteristic time-weighted average concentration of each substance over a typical working week (40 hours) to which a worker can be exposed without adverse health effects. NOMINAL PROTECTION FACTOR: ratio between the concentration of the contaminant in the environment and its possible concentration inside the face mask. REQUIRED PROTECTION FACTOR: ratio between the average workplace concentration of the contaminant and the TLV. (The more toxic the contaminant, the greater the filtering efficiency must be, even at low contaminant concentrations). Nominal protection factors of the most common protective devices: CLASS Protection from gases/vapours Protection from particles, dust and aerosols 1 for gas less than 0.1% in volume (P1 o FFP1) for coarse solid particles without specific toxicity (calcium carbonate) 2 for gas ranging from 0.1% to 0.5% in volume (P2 o FFP2) for protection against solid and/or liquid aerosols classified as hazardous or irritant (silica - sodium carbonate) 3 gas ranging from 0.5% to 1% in volume (large capacity containers carried on the belt) (P3 o FFP3) for protection against toxic solid and/or liquid aerosols (beryllium - chrome, hardwood) PROTEC TION FROM : Facepieces EN 149 Facepieces EN 405 Half masks Full masks P1 dust 4 4 4 5 P2 dust 12 12 12 16 P3 dust 50 50 50 1000 gases and vapours - 20 20 2000 FI LTER USE CLASSES Laboratory and practical performance tests are included to assess compliance with the requirements. EN 140:1998 - Half masks and quarter masks EN 136:1998 - Full face masks EN 143:2021 - Dust filters EN 148-1 - Threads for face masks EN 14387:2021 - Combined gas filters Gases and vapours the right filter for each substance Colour codes Organic gases and vapours (solvents and hydrocarbons) with a boiling point above 65°C Organic gases and vapours (solvents and hydrocarbons) with a boiling point below 65°C Inorganic gases and vapours (chlorine, hydrogen sulphide, hydrogen chloride) Acidic gases and vapours (sulphur dioxide) Ammonia and organic amine derivatives Particles, solid and liquid aerosols Mercury vapours Nitrogen monoxide Carbon monoxide Iodine GU I DE ON HOW TO CHOOSE THE RIGHT FI LTER: