Boiling, baking, airing out: The skills required to make sure you’re safe reusing an FFP2 face mask (equivalent to a KN95 or N95 mask) are more often seen in the kitchen.
To be clear, anyone wondering whether these steps are really necessary before reusing a face mask, should know that pathogens you may have exhaled remain on the inside of your mask.
Put the mask on again without doing anything, and you’re breathing them in.
Also, your possibly infected hands touch the mask every time you take it on or off; from there, it can get in your eyes or nose.
In short, it’s safer to kill bacteria and viruses before reuse.
However, the question arises of how to maintain filter performance after disinfecting a face mask.
Researchers in Germany have found three ways that are easy for the general public to disinfect their masks.
The options are in the oven, in the air and in the cooking pot.
The oven method has come under fire because it’s easy to mess up: If it’s too hot, the filter is damaged; too cold and viruses don’t die.
Chemist Martin Kreyenschmidt opines that boiling your mask in a pot is the best method.
Put the face mask in a tightly sealed bag meant for freezing or boiling, and put in the water for 10 minutes.
“This is a very simple method where you can do little wrong.”
An FFP2 mask can be boiled this way about three times at most.
Before trying this method, be sure to read up on how to do it online first.
The third method is air-drying: Hang the mask up with a hook and leave it to dry for a week.
This can be done up to five times before the mask should no longer be used.
Occupational safety expert Peter Paszkiewicz is sceptical of such reprocessing methods and belongs to those critical of the oven method.
If you want to reuse a mask several times, he says, air-drying is best.
“That’s what we recommend,” he says.
Under no circumstances should the mask be stashed in a pocket or purse.
“Then bacterial cultures develop quite superbly,” he says.
Face masks should hang in the open – ideally, for several days in the sun.
Indications such as “NR” or “R” on the masks are not relevant for everyday users, he says.
NR means the masks should not be reused.
But ”from an infectiological view, this has no relevance; it’s more related to occupational safety”, according to Paszkiewicz.
Self-disinfecting masks are also available.
Special materials in these masks deactivate viruses and bacteria within a certain amount of time, allowing you to reuse the mask safely afterwards.
One solution uses positively-charged textile surfaces to destroy the negatively-charged bacteria and viruses.
Researchers in Berlin have looked at these textiles and found that while the viruses will be deactivated, it takes a few hours.
The SARS-CoV-2 virus particles are not neutralised straight away.
From Kreyenschmidt’s point of view, such a product lulls consumers into a false sense of security, and it’s impossible to say realistically how quickly the protective ability will wear off.
Before buying such a product, be sure to really study its certification and see what standards it meets – this will help prevent you from spending money on a face mask that’s, in the end, useless. – By Tom Nebe/dpa