While The Canadian Shield uses very similar 100% polypropylene non-woven materials for our Semi-Reusable, these Semi-Reusable masks have NOT been tested to meet ASTM F2100-20 requirements for medical-grade masks. It is therefore only considered an unrated mask and should not be used in environments where fluid exposure is of high risk.
Furthermore, different variables such as laundry detergent, water temperature, and other factors can affect the filtration efficiency and durability of the mask. The Canadian Shield always recommends following the included washing and care instructions which accompany all Semi-Reusable Masks. For individuals in environments where there is a moderate to high risk of fluid, spray, or aerosols produced, disposable ASTM-rated medical-grade masks are the best line of defense combined with social distancing and other PPE.