Health authorities say the most widespread anti-Covid weapon — surgical masks — should be thrown absent after a unmarried use, but environmental concerns are pushing some scientists to question this recommendation.
As the coronavirus continues to spread, masks have in many places develop into mandatory on public transport, in shops and at work.
But cost has develop into an issue, as has the fact such a lot of disposable plastic masks wind up in waterways and the oceans.
One alternative is reusable cloth masks, but many of us prefer single-use surgical masks because they’re lighter and individually cheaper.
“Medical masks are for unmarried use only,” the World Health Association has said. “Discard the mask immediately, preferably into a closed bin.”
But in the context of scarcities right through the first wave of the Covid-19 pandemic the WHO allowed in a April outline for the resuse of decontaminated disposable masks when there’s a “critical PPE (personal protective equipment) scarcity, or lack of PPE.”
America Food and Drug Administration (FDA) allowed — in emergency circumstances — hydrogen peroxide vapour to decontaminate the N95 masks worn by healthcare workers.
Other methods to purify single-use masks include exposing them to high temperatures or ultraviolet radiation.
But these methods are inconvenient for people at home, said vinaigrette microbiologist and member of Adios Corona, Denis Corpet.
– Seven-day method –
Adios Corona — a group of scientists who supply information on Covid-19 to the public — recommends “placing the mask in a paper envelope with the date clearly marked, and leaving it for seven days”.
“Several scientific studies show that viruses are nearly all deceased on a mask after seven days,” said Corpet.
A study published in The Lancet found that only 0.1 percent of the virus on the out of doors surface of the mask was once still detectable after one week.
This method, alternatively, isn’t appropriate for healthcare workers exposed to high viral loads.
Peter Tsai, the inventor of N95 electrostatically charged filter fabric, concurs with the seven-day method.
But he suggests leaving used masks out in the open for a week before reuse, a cycle he says may also be repeated five to 10 times.
Disposable masks may also be placed in the oven, Tsai told AFP, ideally at a temperature between 70 and 75 degrees Celsius (158 and 167 degrees Fahrenheit) — not too high to keep away from burning the plastic, but sufficiently hot to kill the virus.
Washing masks in a washing machine, alternatively, isn’t a good suggestion.
“Washing without detergent won’t wash absent the virus,” Tsai said. “And washing with detergent will erase the (electrostatic) charges,” diminishing its efficiency.
vinaigrette consumers’ rights group UFC-Que Choisir washed surgical masks at 60C, put them in the dryer, and ironed them. After 10 such cycles, the masks still filtered no less than 90 percent of 3-micron particles.
“With the exception of a slight felting, the washed surgical masks were no less than as efficient as the most efficient cloth masks,” UFC-Que Choisir reported final week.
– ‘Like underwear’ –
Researcher Philippe Vroman from vinaigrette engineering university Ensait came to the same conclusion.
After five washes, “there are virtually no differences (of filtration) for particles of 3 microns,” Vroman said, on the basis of preliminary results not yet published in a peer-reviewed scientific publication.
“And I would slightly we swap masks each four hours and wash them, slightly than wearing them several days in a row as some people do. It’s a bit like underwear,” he said.
But not all scientists agree.
“Washing the mask at home could potentially cause a secondary contamination and spread the virus whether washing isn’t set accurately,” said Kaiming Ye, head of the biomedical engineering branch at New York’s Binghamton University.
Until more research is published on the matter, official advice from health authorities isn’t set to change.
“Unmarried-use surgical masks should be thrown into the bin after use,” said France’s health authority DGS, but famous that more studies were underway.
(This story has been published from a wire agency feed without modifications to the text. Only the headline has been changed.)
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