Aerosol Penetration Through Protective Fabrics

The aerosol penetration efficiency and quality factor for three Chemical Biological Radiological protective fabrics were evaluated using a particle counting technique. Both parameters characterise aerosol penetration through tested material; the latter accounts for the effect of fabrics air permeability. The overall and size dependent penetrations of 0.03–3 μm sized Sodium Chloride (NaCl) and Di-Ethyl-Hexyl-Sebacate (DEHS) aerosols were measured through fabrics at three different constant air face velocities (5, 10 and 25 cm/s). Penetration was size dependent with the most penetrating particle size (MPPS) at about 0.5 μm. Increasing the air face velocity increased the penetration of ultrafine particles (smaller than 0.3 μm), decreased penetration of the supermicrometer particles (larger than 1 μm) and shifted the MPPS towards smaller diameters. The quality factors were governed by air permeability. The fabrics with higher permeability showed higher quality factor values, thus indicating better protection for a given air pressure drop. The observed dependencies were generally in good agreement with air filtration theory.