In some countries it’s now obligatory to use face masks as soon as you’re out of your home, in some it is only mandatory to wear them indoors or where you can’t keep social distance. We prefer the washable cloth masks (we even made our own) to prevent more pollution and extend the life of fabrics we had like old pajamas and shirts, but due to the lack of a significant decrease of infections, it is now obligatory to wear only surgical or FFP masks (which are single use) in some places.

“With protective gear still in high demand, buying disposable face masks can be difficult, expensive, and can exacerbate shortages for medical personnel.“ For that reason, we want to share some visuals from organizations and education institutes who indicate how to disinfect and extend the life of these masks safely.

Disinfect N95 & Surgical Masks • Disinfect FFP2 Masks • Guidelines on Reusing single-use Masks

First, we want to point out the Do’s and Don’ts when wearing a medical mask, see the infographic below provided by the WHO:

How to Disinfect certain kinds of Masks
(N95 respirators and Surgical Masks)

IMPORTANT: Not all N95 masks can or should be disinfected and reused. Learn more about whether your respirator can be reused here.

Researchers at Columbia University’s Lamont-Doherty Earth Observatory investigated how to safely disinfect and reuse disposable face masks. Their research — published in April and detailed in their blog post — showed that disinfecting certain kinds of N95 respirators and surgical masks by baking them at 170 degrees F did not affect most masks’ ability to filter out virus-sized particles, even over 10 cycles of disinfection in the oven.

It’s important to follow a few key steps in order to disinfect your mask without damaging it and putting yourself at risk. Find the visual of the steps (summarized) below, for more details please go here.

How to Disinfect FFP2 Masks

The guide below (images and text) was published by the Münster University of Applied Sciences (roughly translated from German to English):

“FFP2 masks are used in healthcare in areas with an increased risk of infection. The FFP2 masks, which are designed as single-use products, must be disposed of after use to avoid further risk of infection. When using FFP2 masks for private use (e.g. shopping), the FFP2 masks are less likely to be exposed to pathogens. When used correctly, FFP2 masks offer better protection than medical face masks (surgical masks). However, their availability is limited. Therefore, extending the life of FFP2 masks for private use can be a way to workaround this problem.

Everyone wearing a mask leaves pathogens of their own nasal, throat and skin flora in the mask. These cannot be completely inactivated with simple procedures. For that reason, the mask should not be shared but used only by the original owner.“

Method 1: 7-Day Air Drying

Assuming that a reduction of over 95% minimizes the possible risk of infection to an acceptable level, FFP2 masks should not be worn again until the seventh day at the earliest. 

Prepare seven hangers or clips for each hanging row (per person). Find a dry place free of other objects, with sufficient space for seven masks hanging next to each other (e.g. hall, living room, office – not kitchen or bathroom because of the humidity). Keep enough distance for each row. Identify the person and days of the week so you can always see exactly which mask can be worn next. You can also stretch a clothesline and hang the masks there with enough distance from each other with clips. Make sure that the place designated to hang the masks is out of the reach for children.

You should only repeat this “drying cycle” five times. Dispose of the mask you wear for the fifth time in the household waste. Even if you notice that a mask is defective, that you were coughed up directly or that a mask is particularly worn out, we recommend that you dispose of it directly, even before the five drying cycles have expired.

Method 2: 80°C Drying in the Oven

By drying the mask at 80°C for 60 minutes, SARS-CoV-2 can be completely inactivated. Preheat the oven to 80°C (top and bottom heat). Cover the oven tray/grid with clean baking paper. Place the dry mask and a roasting or oven thermometer on the covered tray.

Once preheated, slide the grid and mask(s) into the oven. Make sure there is enough distance between the masks and the top and bottom of the oven (approx. 10 cm; small ovens are unsuitable). Leave the FFP2 mask in the closed oven for 60 minutes, do not open it in between. After 60 minutes, turn off the oven and let the mask cool down on the rack outside. The mask should only be treated up to five times this way and then disposed of with the household waste.

IMPORTANT: Other methods like steaming, microwaving, using a washing machine, dishwasher or UV lamp have been reported to damage the mask or not to inactivate the virus sufficiently.

Summary of current international guidelines on Reusing single-use Masks and Respirators

“Extended use and re-use of single-use surgical masks and respirators (with or without reprocessing) should only be considered in situations of critical shortage. Where extended use or re-use is being practiced, healthcare organisations should ensure that policies and systems are in place to ensure these practices are carried out as safely as possible and in line with available guidance. Areas of guidance lacking clarity and consistency warrant further attention and investigation.“

DISCLAIMER:
please consult your local authorities and medical services. New insights might change the official recommendations. Laws and guidelines may differ and depend on local authorities. The views are not a substitute for professional medical advice.