Wearing a face covering became a condition of entry to indoor public spaces in the UK in late July — and, according to at least one poll, some people haven’t washed their reusable masks or changed their disposable ones since.
As many as 85 per cent of us aren’t washing our fabric face coverings properly in between uses, and 15 per cent have never washed theirs, suggests a YouGov survey from August.
And among those who opt for disposable masks, more than half aren’t binning them after use, but re-wearing them multiple times.
A YouGove survey found that as many as 85 per cent of us aren’t washing our fabric face coverings properly in between uses. (Stock image)
‘A mask is primarily worn to protect others from infected droplets that our breath might release into the air,’ says Dr Tina Joshi, a lecturer in molecular microbiology at the University of Plymouth.
‘It can also help stop us breathing in anyone else’s infected droplets. But it will only work as a barrier if we use it properly.’
That means washing and drying reusable masks in between uses, and disposing of single-use ones after each outing.
Otherwise the mask may become contaminated and any virus on it could spread to the wearer, or to others if it is left lying around the home.
But what is the ‘proper’ washing technique? And does it even work? As the Scientific Advisory Group for Emergencies (Sage) noted in a recent report, there is little, if any, evidence to show how effectively washing removes the coronavirus from masks.
UK Government guidelines advise washing reusable masks ‘in line with manufacturers’ instructions at the highest temperature appropriate for the fabric’, while the World Health Organisation recommends washing them ‘at least once a day’.
The survey also found that more than half of those wearing disposable masks are not throwing them after use. (Stock image)
‘I would go further and say you shouldn’t be washing it just daily, but after every use,’ says Dr Joshi. ‘So every time you’ve been out and come home, remove it immediately, wash it, and wash your hands. Treat it like it’s contaminated once you’ve worn it.
‘It may sound excessive, but if you’ve been around others outside your bubble you can’t know whether you’ve picked up infected droplets or not.
‘You don’t have to run it through the washing machine each time: any biological detergent is suitable. I wash mine by hand with washing-up liquid, scrub it, and put it out to dry.’
Dr Joshi adds that you need at least two reusable masks, ‘so you’ve always got one being washed and one that’s clean and ready to go’.
However, the ‘highest temperature’ mentioned in government guidelines is not vital, she believes. ‘Most biological cleaning agents would work at lower temperatures,’ she says.
Enzymes in the detergents break down the protective envelope around the virus and so destroy it — they work in the same way as 70 per cent alcohol hand sanitisers.
Washing by hand at lower temperatures also means you are less likely to degrade the material and damage the mask — which could make it less effective as a barrier to virus droplets.
If you’re out all day, there are ways to disinfect your mask on the move, says Dr Joshi.
‘I’ve got 70 per cent ethanol in the lab, and I’ll spray it on the exterior of my mask throughout the day. Any 70 per cent alcohol spray will do the same job.
‘The alcohol will disrupt the virus sheath and disable it — but it won’t affect whatever’s embedded in the fabric layers. That’s why the whole washing process is needed as often as possible.’
To avoid contamination in between uses, you should store your fabric mask, or your spare disposable ones, in a clean, resealable plastic bag.
Disposable masks have some distinct advantages over cloth versions, says Dr Joshi.
‘Unlike the varied styles of cloth or home-made masks out there, you know you are getting something that’s got two or three ply layers,’ she says.
‘Also, the blue outer layer is covered with a chemical that makes it slightly hydrophobic — or water resistant. As the virus is carried in droplets, if the water cannot get through, it makes it much harder for the virus to.
‘Though you have to weigh up these benefits with other things — such as being bad for the environment and the cost.’
Perhaps that explains why, according to the YouGov poll, 56 per cent of people are reusing disposable masks — 34 per cent of them up to three times.
This poses the same risk as neglecting to wash a reusable mask, as the covering becomes a potential vector for infection.
So could you just wash a single-use mask? ‘They’re simply not designed to be washed,’ warns Dr Joshi. ‘For one thing, the heat and detergent may damage the repelling agent on the outside, which will make it less effective.
‘And, quite apart from anything else, little fibres start to escape from the fabric, which will tickle when you breathe.’
As a last resort you could spray a mask with alcohol between uses, but you must ensure it dries properly as the virus travels well in damp environments.
‘Wearing a dirty mask poses a risk to you, certainly,’ says Dr Joshi. ‘But for preventing your droplets escaping and infecting others, it’s better to wear something than nothing at all.’