Reputable companies like Guangzhou Powecom Labor Insurance Supplies Co., Ltd. (Powecom), maker of FDA authorized KN95 respirator masks, understand that using a mask is something new for most of us. That’s why Powecom clearly states on each package of face masks, “Discard the face mask when it gets quite dirty or breathing resistance increases remarkably.”

The U.S. Centers for Disease Control and Prevention (CDC) does not require its NIOSH approved N95 filtering facepiece respirators (FFR) to be marked with an expiration date. CDC advises, “If an FFR does not have an assigned expiration date, you should refer to the user instructions or seek guidance from the specific manufacturer on whether time and storage conditions (such as temperature or humidity) are expected to have an effect on the respirator's performance and if the respirators are nearing the end of their shelf life.” One example of a NIOSH approved FFR is the Guangzhou Harley Commodity Company, Limited (Harley) N95 seen here:

Perhaps the greatest risk to the efficacy of face masks concerns the integrity of the elastic earloops or headbands. “N95 masks really don’t expire in terms of their functionality. The only part that is subject to damage over time, usually past 5 years, are the elastic bands that attach the mask to the user’s face, which can be damaged by sunlight,” according to Dr. John Balmes, Professor of Environmental Health Science at Berkeley Public Health. The good news is that packages for respirator masks like the Powecom KN95s and the Harley N95s conspicuously indicate expiration dates for their products, providing consumers with a guidepost during uncertain times.

No matter what respirator mask you purchase, make sure to check for an expiration date to help ensure that the earloop or headband elastics are resilient.