In recent weeks, due to shortages of N95 respirators, the FDA approved the use of KN95 and other alternative respirators. However, officials have discovered that counterfeit respirators have flooded the marketplace. Additionally, some respirators that were pulled for random testing failed to meet performance standards.
You should discontinue the use of KN95 and other alternative respirators until you can confirm their authenticity against the FDA’s list of approved alternatives to N95 respirators. You should also verify their performance through fit-testing.