Fabric Barrier Mask Category 1 - NSU 1: Individual mask for use by professionals in contact with the public. Also suitable for general public use. Materials performance has been measured by DGA Maitrise NRBC laboritoriesm 5 rue Lavoisier, 91710 Vert-le-Petit, France (RP/20-3023/DGA MNRBC/2000305/NP) and found to be effective up to 50 washes (report IFTH 2020-06-03-052-50): Filtration efficiency for 3 μm particles > 90% Breathability - Air permeability (for a 100 Pa vacuum pressure) >96 L/m²/s.   Offers protection for up to 50 washes  Can be worn for up to 4 hours at a time (must be washed after each use) Mask dimensions:  200mmW  x175mmH Composition: Made from 2 layers of Polycotton fabric (65% polyester, 35% cotton) and a Polypropylene core (3 layer total) OEKO-TEX certified materials (without harmful substances) Contains latex