After boiling, the mask cannot play a protective role and cannot be used again. In addition to wet disinfection will destroy the hydrophobicity of the mask material, high temperature “boiling” will deform the fiber material of the non-woven fabric, so the filtering performance of the mask will be more discounted after “boiling”. If you must “boil”, it is recommended to last at least 15-30 minutes in boiling water and then dry in the sun, but only as an ordinary veil mask when used.