Cleaning and Reusing Face Masks and Other Protective Face Coverings

How is this disease spread? Like many respiratory viruses, including the flu, the COVID-19 virus can be spread in tiny droplets released from the nose and mouth of an infected person as they cough, sneeze, or speak. It has been reported that a single cough can produce up to 3,000 droplets. These droplets can land on other people, clothing and surfaces around them, but some of the smaller droplets can remain in the air.

For some time the Centers for Disease Control and Prevention (CDC) maintained that the only people recommended to wear face masks were people who were ill or those who were treating them. That notion stemmed from the idea that basic medical masks do little to protect wearers, and instead primarily prevent sick people from spreading infectious droplets from their noses and mouths. Plus, limited supplies needed to be prioritized for frontline health workers.

The CDC, citing new data that a “significant portion” of people infected with the novel coronavirus can spread the virus to others even when they don’t have symptoms, revised its recommendation saying that people should wear cloth face coverings “in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies).” . Now the CDC and a growing number of California officials are recommending that people wear face coverings or masks when out doing essential tasks, such as grocery shopping and going to medical appointments.

But How Do You Keep Your Face Coverings Clean?

So many of us are obtaining and using masks or scarves to protect ourselves from others and to prevent the inadvertent spread of the disease from those of us that unknowingly have the disease. Once you start using masks or cloth scarves the same question arises: “how often should they be cleaned and how do you clean them?” The following is a summary of my research into this question. I’m not advocating any one method but simply listing some cleaning methods that I found to have merit. The cleaning method you choose should be tailored to the types of masks you are wearing, the frequency needed for cleaning, and the resources available to you.

First, cleaning and sanitizing should be performed after each use or, at a minimum, daily.

For cloth masks and scarves, it turns out that simply laundering them should kill the COVID-19 virus. This process is analogous to washing your hands with hot water and soap. The action of soaps and detergents break down the outer lipid layer of the virus and this helps kill the virus. If you have contaminated clothes or fabrics that need to be disinfected, the UK's National Health Service (NHS) recommends washing at a high temperature (140 °F) along with a product containing bleach, which will maximize the disinfectant effect. However, that's only for high-risk clothing. For regular clothing, it's the drying that counts. That's because the heat of a tumble dryer ranges from 135 to 150 °F, and while a washing machine provides damp places for bacteria and fungus to spread, the dryer doesn't. You may want to place the masks or scarves in a mesh bag to protect them from extra wear.

Second, there are some important commonsense rules for putting on and taking off masks and face coverings that will help keep them clean. The most important are the following:

1. Wash your hands before handling a mask and placing it on your face,

2. To remove the mask, remove it from behind (do not touch the front of the mask); and

3. Store your used mask or face covering in a plastic bag or Ziplock bag until it can be cleaned and sanitized, or discard immediately in a closed bin or sealed bag and wash your hands.

Now, how to clean and sanitize your mask or face covering.

Remember, the CDC maintains that there’s not any proven way to disinfect one-time surgical masks. Cleaning and sanitizing masks are really stopgap measures that many are employing due to current mask shortage, but it’s not the best practice! The best practice would be single use. So, with that in mind, here are a few different ways to clean and sanitize your masks for reuse.

Cleaning Your Masks

There is a difference between cleaning and sanitizing your masks. You can easily clean your masks with ordinary hot water and dishwashing soaps like Dawn. This will take the spittle of the inside of the mask, take the sweat out of the mask, and get it back to its original color. However, it will likely not sanitize your mask. To kill the germs, you will have to implement one of the techniques listed below.

Using Heat to Sanitize Your Masks

The Hot Water Method – There aren’t published studies on how COVID-19 stands up to various temperatures, but the World Health Organization (WHO) found that 132.8 °F (56 degrees Celsius) is hot enough to kill the coronavirus that causes SARS. Other tests found higher temperatures, up to 149º F (65º C), are more effective. I would recommend placing the mask into a container and then adding boiling water to it. Let it soak in the water until the water cools to room temperature. Others have recommended suspending the masks over the steam from a a pot of boiling water to kill the virus. Be sure to dry the mask completely before using it.

Oven Method - Place the mask in an oven preheated to 158º F and “cook” the mask for 30 minutes.

Dryer Method - Place the mask in your dryer and dry on high heat for 30 minutes.

Using Chemicals to Sanitize Your Masks

The US Environmental Protection Agency (EPA) has published a list of disinfectants and active ingredients that can be used against the COVID-19 virus called List N: Disinfectants for Use Against SARS-CoV-2, the virus that causes COVID-19.

Here are the most common and easiest ways to sanitize your masks using household chemicals:

Soak in a Diluted Bleach Solution - To make a bleach solution, mix 5 tablespoons (1/3 cup) bleach per gallon of water (or 4 teaspoons bleach per quart of water). Let the masks soak in the diluted bleach solution for 5 minutes. After this period of time, rinse the mask several times to remove any residual bleach from the mask. If you have diluted the bleach properly, you should not smell any bleach after you rinse the mask. Let the mask dry completely before reusing. Be sure to follow the bleach manufacturer’s instructions for application and proper ventilation. Never mix household bleach with ammonia or any other cleanser.

Peroxide Solutions – Hydrogen peroxide can also be an effective sanitizer. According to the CDC, a solution of 3% hydrogen peroxide mixed with 97% water is effective. Note that the typical bottle of hydrogen peroxide that you buy at the drug store is already diluted to a 3% solution so no further dilution is necessary. It is recommended that you soak the mask for at least 10 minutes. The EPA puts hydrogen peroxide high on its list of recommended disinfectants for SARS-CoV-2 and cites particular peroxide-based product names as well.

Alcohol Solutions – To make an alcohol solution, mix at least 70% alcohol with water. Rubbing alcohol (isopropyl alcohol) is best for this. Soak the mask in this solution for 10 minutes. Do not use alcohol on surgical masks because it will dissolve the waterproof coating placed on the mask when manufactured. Once the waterproof coating is gone the mask will allow liquids to pass through the layers of the mask and this will deteriorate the efficacy of the mask.

The “Do-Nothing” Option

This may be the preferred option for those of you that have 5-7 masks that you can put into a service or use rotation. This option relies on the thought that the COVID-19 virus can only survive on a dry surface for several (3-4) days. To use the method, place the used mask on a paper towel by a window the receives sun light. Allow the mask to sit, undisturbed in this spot for a period of 4 days. After this time, any potential viral contaminants should be dead and the mask to be ready for reuse.

I strongly recommend that you do your own research. Understand how to perform the cleaning and sanitizing operations for the masks and facial coverings in your possession, and the strengths and weaknesses of each method. Select a method that you are comfortable with and be careful of cross-contamination during cleaning and sanitizing operations. The simplest methods are probably the best. At my house, I am cleaning and sanitizing in one step. I place my used masks in a mesh bag, wash them in the washing machine with bleach, and dry at high heat. I am using a rotation of 7 masks and cleaning them after every use.

Remember to properly and safely discard and dispose of masks and cloth face coverings that: