Particulate matter refers to a very broad concept. All kinds of dust, smoke, acid mist, and spray paint mist in daily life and agricultural production belong to non-oily particulate matter. The particulate matter and coke oven smoke contained are classified as oily particulate matter. Most of these particles contain acid, alkali or have certain toxicity to the human body. Therefore, "KP/P" and "R" type protective masks should be worn on specific occasions to prevent these particles from damaging and destroying the human respiratory tract.

In daily life, we rarely come into contact with a large amount of oily particles, and the particles that need to be protected in the hospital are not oily. Therefore, "KN/N" masks can fully meet the needs of daily work, life and medical treatment.

For the selection of the filter level, is the closer to 100 the safer it is? Is it necessary to upgrade N95 masks to N99 or even N100 masks in daily life? In theory, higher filtering levels do indeed filter better. However, we have to consider that in actual use, masks with higher filtration efficiency are often accompanied by stronger breathing resistance, which can lead to poor breathing and even hypoxia when worn for a long time; people with underlying lung diseases and the elderly may also suffer fatal blows . Therefore, in order to ensure tightness and reduce breathing resistance, high-level protective masks such as N99, N100, and FFP3 usually have special designs.

Besides filtration efficiency, what else should we pay attention to?

When using protective masks, not only should pay attention to the filtration efficiency, but also pay attention to the tightness of the face after wearing. The filtering efficiency of the mask can only be guaranteed if the mask is fully fitted to the face and does not leak air. If the mask is not worn properly because the breathing resistance is too large, the edge of the mask leaks, and the protective effect will be greatly reduced. When wearing, pay special attention to the size and shape of the mask, and choose the model that best matches your face shape.

The length of time the mask is worn is also critical. Wearing it for a long time can lead to internal humidity, which not only affects the filtration efficiency, but also greatly increases air resistance. Therefore, it is generally recommended to replace the mask after 4-6 hours of use; when the mask is obviously wet or breathing is obstructed , need to be replaced immediately.

For the choice of protective masks, it is not that the higher the filtering level, the better, the one that suits you is the best.