The problem is that the value proposition of layering starts to fall apart if a mask is so thick that it gets sweaty: Cotton and other materials can become less breathable when wet. Moisture from our breath can build on the inside, too, as we breathe harder to cool ourselves. And wetness aside, fabric masks lose value if they’re so thick that they become overly burdensome to wear and people take them off.
Once you’ve calibrated your mask to balance safety and livability, then it’s time to worry about it falling apart. This brings us to washing. Any material degrades with washing, as the fibers grow slightly thinner and farther apart. Avoiding overwashing is especially relevant to masks, because the tightness and integrity of the fibers is essential to their function.
Read: Refusing to wear a mask is an empty act of defiance
So, in our ramshackle approach to self-masking, there is good reason to think outside the box. One of the things we could be using more to our advantage during this pandemic is time. The virus can hang around for a few days on some surfaces, but it lives longer on hard surfaces such as metal doorknobs than soft ones such as cardboard or cloth. If you waited a week to reuse a mask, I see no reason that you shouldn’t feel certain it was free of the virus. Bacteria and fungi can grow on all sorts of mediums, but viruses need a host. Without one, their days are numbered.
Light is also our friend. The Centers for Disease Control and Prevention recommends washing your mask like you would any other piece of laundry, by machine or hand, and then leaving it to dry in direct sunlight. This latter part may deserve more emphasis than the former. Intense UV rays can kill the virus in less than an hour. This doesn’t mean you’re safe from infection simply because you’re outside, but it does mean that surfaces and materials exposed to direct sunlight will carry the virus for less time than they would in the dark. Sunlight is a tool worth keeping in mind for specific uses like disinfecting makeshift masks, even if it can’t be inserted into people, as President Donald Trump has suggested.
In sum, this may be the surest way to get the safest, longest life out of your mask: Have several masks, made to fit well around your nose and mouth. Make them as heavily layered as you can tolerate. After wearing them for a day or so, or in a high-contact scenario, let them sit for a few days in a sunny, out-of-the-way place. Between the effects of time and light, there should be little need for running a washing machine or going through the hassle of hand-washing your masks. Well, unless they just smell terrible. In that case, maybe it’s your teeth that need cleaning.
If it sounds like I’m making this up based on best guesses, I am. Everyone is. We would ideally all be wearing surgical masks, and disposing of them frequently, but we didn’t prepare accordingly. So for all their flaws, cloth masks are important: Making them effective enough for use in daily pandemic life means we’re freeing up medical-grade masks for people who really need them, especially in places where they are still in short supply, such as the United States. Health-care workers around the world still need proper personal protective equipment more than a random guy named Gene who wants to go to the store to buy snacks.