Coronavirus: HK scientists look into disinfection and reuse of face masks

04-Apr-2020 Intellasia | South China Morning Post | 6:02 AM Print This Post

Hong Kong scientists are looking into disinfecting and reusing masks amid a Covid-19 pandemic exacerbated by a persistent shortage of protective gear, a top infectious disease expert has revealed.

Professor Yuen Kwok-yung from the University of Hong Kong said the options were being studied for both N95 respirators, which are used by health care workers when handling suspected and confirmed coronavirus patients, and standard surgical masks.

“We have to be innovative, because shortages cannot be met within a short period of time,” Yuen said in an online dialogue session organised by HKU on Thursday evening. “All these masks would not suddenly fall from the sky.”

Yuen said experiments were being done to see whether N95 respirators could be disinfected with hydrogen peroxide vapour and used again.

“This can be done. These N95 respirator masks can be used many times afterwards,” Yuen said. “We of course label all these masks, make sure that they are sent to the same person again after disinfection.”

Hong Kong would not be the first place to clean and reuse the face coverings. In the US in late March, the Food and Drug Administration authorised a company to decontaminate N95 respirators using a similar method, with each mask being reused no more than 20 times.

Yuen added that researchers in the city were also studying the efficacy of disinfecting surgical masks, worn by almost everyone on the streets of Hong Kong, with ozonisers, devices which kill germs with ozone.

He later told the Post that the disinfection and reuse of N95 respirators, which was still at exploratory stage, was intended for public hospitals. The disinfection of surgical masks, with ultraviolet or ozone, would be for the community, if there were not enough to go around.

Supplies of masks and protective gear have run low globally as the coronavirus has spread all over the world. Many countries have banned the export of masks and other protective items.

Public hospital officials in the city have said their stocks of masks could last for about one to two months.

In the online session, Yuen revealed that he also uses alternative ways to make each mask last longer. Underneath each standard surgical mask, he said, he wears a reusable cloth mask. After he uses it, he disinfects the surgical mask with an ozoniser.

“Then hang [the mask] up, let all the ozone disappear, and then I use it again, but again with a reusable cloth mask inside,” he said.

Yuen urged the public to “take the epidemic seriously”, on the day that the number of confirmed local infections passed 800. He reminded people to wear a surgical mask, wash their hands frequently and adhere to social-distancing measures.

“The number [of cases] would rocket if things are not being done decisively,” he said.


Category: Hong Kong

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