Pay attention to the purchase of masks
The outbreak of new coronaviruses continues, and the number of confirmed cases continues to rise every day. Masks have become a necessity for everyone to go out. The virus can spread through droplets, and wearing a suitable mask becomes an important part of epidemic prevention. There are a variety of masks on the market. What precautions should be taken to prevent the purchase of inferior masks?
According to ASTM International standards, masks must pass various filtration rate tests and be clearly listed on the package before they are sold on the market. There are three types of labels: BFE, PFE, and VFE, which are the test results of masks filtering particles of different sizes.
BFE (Bacterial Filtration Efficiency) bacteria filtration rate: can filter particles 3 microns, blocking pollen, flying maggots
PFE (Particle Filtration Efficiency) particle filtration rate: can filter 0.1 micron, block influenza, SARS and other viruses
VFE (Virus Filtration Efficiency) virus filtration rate: can filter particles from 0.1 to 5 microns.
In addition to the BFE, PFE, and VFE standards, some masks also include a "PM2.5" mark, which means that they can block 2.5 micron particles (Particle Matter). In addition, there is the familiar "N95", which is one of the nine anti-particulate masks certified by the National Institute of Occupational Safety and Health (NIOSH); the mask can block 95% of non-oily particles with a diameter of 0.3 microns or more. According to Xu Changchang, a professor of respiratory sciences at CUHK, N95 masks can block 95% of suspended particles in the air, and have a better blocking ability than surgical masks, which can be used to prevent infectious diseases such as lung infection.
When you buy surgical masks, in addition to choosing a three-layer design, you must also read the labels on the mask box, such as the place of production and the date of production, whether they meet international standards. In addition, according to the Consumer Council ’s tests on masks on the market, the results show that most models have a bacterial filtration efficiency higher than 95%, but some masks have a filtration efficiency of 95% or below. Everyone should consider carefully when buying.