Masks have a shelf life, and the length of time depends on many factors such as the material, technology and user habits of the mask. The shelf life of disposable masks is generally two years, and it is better to use within the shelf life. It is not recommended to use disposable masks that are beyond the shelf life, disinfect them as much as possible.

1. On the fabric: because the surgical face mask is directly in contact with the face and mouth, its breathability, skin flexibility, stretchability and durability are the main factors that determine the length of use of the mask. Among them, breathability is directly related to the cleanliness of the mask, and the mask can only play its protective role if the mask is clean, and will not become a breeding ground for germs. And good skin softening can avoid itching and allergies when the face and fabric are rubbed, which can also extend the use time of the mask to a certain extent. As for stretchability and durability, it is related to whether the shape of the mask remains the same.

2. Technical aspects: With the high incidence of air pollution such as smog, the intensity of air pollution continues to increase. To improve the life span of masks, we must constantly update and improve the technology. This not only requires the introduction of new filter material technology, but also requires the improvement of the fitting technology between the mask and the face.

3. Usage habits: If the fabric and technology of a mask reach an excellent standard, the shelf life is about 2 years. However, if the method of using the mask, as well as the cleaning and maintenance methods, are not carried out according to scientific methods, then its lifespan will be greatly reduced.

Disposable masks not only have a shelf life, but also have a valid period of use. Under normal circumstances, if it is used outdoors, such as subways, buses, supermarkets, shopping malls and other public places, disposable masks need to be replaced every 4-6 hours, but if it is in a new pneumonia virus epidemic area, it is recommended to replace it once every 2 hours.