Subsequently, MacIntyre et al. compared the effectiveness of cloth mask vs. medical mask in a hospital. Their results indicate that the penetration of the medical mask by the particles was 44% while the penetration for the cloth mask was almost 97%. Respirators like N95s and KN95s are designed to form a seal around the mouth and nose, for example, while reusable cloth and Medical masks often have a looser fit. Features like adjustable ear loops and an adjustable nose bridge help you improve the fit of your mask, as do mask fitters or braces. The knot-and-tuck method can also create a tighter fit when you wear a disposable face mask. Although more than 60 percent of Americans are up-to-date on their COVID-19 vaccines, the pandemic isn’t over — and despite the lifting of mask mandates in many parts of the United States, neither is mask-wearing.
However, researchers are testing ways to disinfect and reuse them. Some masks and respirators offer higher levels of protection than others, and some may be harder to tolerate or wear consistently than others. It is most important to wear a well-fitting maskor respirator correctly that is comfortable for you and that provides good protection. MacIntyre C.R., Seale H., Dung T.C., Hien N.T., Nga P.T., Chughtai A.A. A cluster randomised trial of cloth masks compared with medical masks in healthcare workers. Logically, other regulations also establish their particular level of effectiveness. Table 2below summarizes the FFP respirators that are recommended as PPE against COVID-19, according to the standards of different countries .
However, we cannot forget the importance that the World Health Organization has played in this context. It initially made different recommendations for the groups including healthcare personnel, people in direct contact with the infected and people with symptoms (Holland et al., 2020, Jansson et al., 2020) on the one hand, and for the rest of the people on the other. Therefore, on 20 April 2020, it still recommends that “If you are healthy, you only need to wear a mask if you are taking care of a person with COVID-19” . Depending on the infection and hospital occupancy rates where you live, you might be feeling like it’s safe enough to wear a less constricting surgical-style mask. While this type of mask tends to gap and leak at the sides, any mask is better than no mask at all.
Lists of respirators that are NIOSH-approved can be found on the NIOSH-Approved Particulate Filtering Facepiece Respirators webpage. Jinadatha C., Simmons S., Dale C., Ganachari-Mallappa N., Villamaria F.C., Goulding N., Tanner B., Stachowiak J., Stibich M. Disinfecting face mask personal protective equipment with pulsed xenon ultraviolet as a risk mitigation strategy for health care workers. The use of ethylene oxide, which is widespread in hospitals, is less safe than hydrogen peroxide vaporization and less environmentally friendly.
Subsequently, FFP respirators were subjected to a fit test to verify that they fit properly and that the filter material continued to be a good barrier against particles. The fit test results for an untreated FFP respirator showed an average value of 162. Therefore, a reprocessed FFP respirator must have a minimum average value of 100 to pass the fit test. Based on these, it was preliminarily concluded that “double sterilization using a short process with hydrogen peroxide gives an acceptable result” . We must remember that either PPE (-FFP respirators) or medical face masks manufactured according to technical standards, require that they be discarded after use, since they are heat sensitive and are not designed to undergo a process as severe as sterilization . This is why manufacturers like 3M initially advised against the sterilization process .
Regarding the comparison with non-certified or homemade masks, Rengasamy et al carried out an evaluation of the filtration efficiency of this type of mask against particles. To do this, they tested these masks for 20–1000 nm size particles, specifically, polydisperse and monodisperse aerosols, at two speeds. Since there are a wide variety of homemade masks with Medical masks various characteristics, they used the five main types made of sweatshirts, T-shirts, towels, scarves, and cloth in the test. Furthermore, they compared the results with the penetration levels presented by N95 respirators. Their results indicated that these masks had 40–90% instantaneous penetration levels at a low speed and between 9 and 98% at a higher speed.