The Estella washable face mask uses military grade filtration technology with an inhibition rate of 99% of staphylococcus aureus, escherichia coli, candida albicans, Klebsiella and other harmful bacteria and particles for the fabric as well as dust mites and has successfully passed the following safety tests:- Skin-friendly- Has high bacterial filtering efficiency- Anti-flowing and flowing particle barrier- It does not sensitize the skin