According to the standards of the American Society for Testing and Materials (ASTM), masks need to pass various filtration efficiency tests before they are launched on the market and be clearly marked on the packaging. Most masks in the United States pass the Nelson Laboratory Standard to test the filter rate of masks.
European, Taiwan and Japanese masks are tested with BFEW and VFEW particulate filter rate results.
BFE (bacteria filtration efficiency)
For particle size: 3 microns
VFE (virus filtration efficiency)
For particle size: 0.1-5 microns (average 2.8 microns)
The different particulate filtration rates of the mask are generally represented as percentages. VFE is the highest filtration rate standard. Pay attention to the percentage of relevant standards before purchasing. The higher the number, the more it can block more particles in the air. According to the standards, only the BFE test is not sufficient to block the virus from droplets, and it is better if the VFE is marked as 95% or more.
The nanofiber membrane in the Face Guard Pollution Scarf has been tested according to ASTM F2100 and EN 14683.