Metal leaching from antimicrobial cloth face masks intended to slow the spread of COVID-19

Abstract Global health organizations recommend the use of cloth face coverings to slow spread COVID-19. Seemingly overnight, companies whose primary business is in no way related healthcare or personal protective equipment—from mattresses manufacturers big box stores—transitioned into “mask business.” Many advertise antimicrobial masks containing silver, copper, other antimicrobials. Often, techniques used load such antimicrobials onto mask fibers are undisclosed, and potential for metal leaching from these yet unknown. We exposed nine so-called “antimicrobial” (and one 100% cotton control mask) deionized water, laundry detergent, artificial saliva quantify leachable silver copper that may occur during washing wearing. Leaching varied widely across manufacturer, metal, solution, but some cases was as high metals contained as-received after 1 h exposure.