The factors affecting the anti-haze effect of masks are various, mainly including the tightness of masks, high-quality filter materials, and wearing methods. One of the important factors is whether the tightness of the masks is good. Filtration efficiency is one of the most critical technical indicators of masks, but the detection of mask filtration efficiency is under the assumption of sealed conditions, such as N95 masks can block 95% of particulate matter during testing. But if there is no seal and harmful particles pass through elsewhere, the data in the standard will be meaningless.

The anti-haze masks on the market have many defects in the airtight design. For example, if the edges around the masks are not properly sealed, it is easy to cause gas to directly enter the respiratory system without filtering the membrane. Especially the nose bridge is raised relative to the face. When wearing a mask, it is easy to form a large gap on both sides of the bridge. Although most masks now have aluminum strips on the bridge of the nose to shape the seal, it is difficult to achieve the desired effect.

This means that even if the merchant claims how advanced the filtration membrane is and how high the filtration efficiency is, the actual use of the mask is difficult to ensure that 100% of the gas penetrates the filtration membrane, and a considerable amount of haze can still pass through the mask. The filter enters the respiratory system. In this way, a large number of PM2.5 particles can also enter the alveoli, and then enter the capillaries through the walls of the alveoli, and then enter the entire blood circulation system. Accumulating over time will seriously affect physical health.