Health-care workers need to receive training and take a fitting test before using an N95 mask. The CDC suggests a surgical mask underneath the cloth mask may provide additional protection when using N95s is not feasible. Loosely knit cloth masks are the least effective but may offer an extra layer of protection if worn under a surgical mask. A non-fit-tested respirator can offer no better protection than a surgical mask.
The surgical mask fit study described earlier suggests that a poor fit can be partially compensated for with a good collection of filters, but it does not approach the level of protection offered by a respirator. Surgical masks are not evaluated using worst-case filter tests, so it is impossible to know which offers better filter performance. While N95 respirators are best-in-class, you can still get levels of protection and fit with other mask methods. According to scientists at the National Institutes of Health, N95 respirators can effectively decontaminate themselves and retain their function for up to three uses.
In addition, a study that, it should be noted, has not been reviewed by peer-reviewers looked at how N95 respirators could be re-used using various cleaning strategies, like rotating several masks or subjecting them to heat. While N95 and KN95 masks are disposable masks, a number of individuals have found ways to reuse them effectively. The reason that N95 masks are designated single-use is that they are classified as medical masks, says Erin Bromage, associate professor of biology at Dartmouth College, UMass. Frontline physicians and critical health workers performing the highest-risk procedures should have access to the highest levels of protection available in NIOSH-approved N95 respirators; Sickbert-Bennett and colleagues4 demonstrated that the reused, expired supplies of N95 masks are safe and provide excellent alternatives to the standard, single-use N95 masks.
Together, these and other emerging evidence suggests surgical masks and alternatives to N95 will continue to provide safe practices for clinicians and healthcare workers. Like N95 respirators, surgical masks and procedures are used by healthcare workers, and their safety depends on having an adequate supply. N95 respirators and surgical masks are examples of PPE used to protect the wearer from particles or fluids contaminating their faces. Facemasks may or may not achieve some level of liquid barrier or filtering effectiveness; thus, they are no substitute for N95 respirators or other filtering facepiece respirators (FFRs), which offer respiration protection to the wearer, or surgical masks, which offer liquid barrier protection to the wearer.
The FDA regulates surgical masks and surgical N95 respirators differently depending on the intended use. Because National Institute of Occupational Safety and Health (NIOSH)-approved N95 masks are no longer available, the CDCs guidance indicates individuals can opt to use NIOSH-approved N95 masks instead of cloth face coverings for personal use. For readers disappointed by our advice to discontinue making cloth masks for yourself or health care workers, the authors suggest that you should instead contribute toward locating N95 FFRs and other types of respirators for health care facilities. Best practices for using N95s call for periodic, individual fit tests, and checking for a seal when worn.