Health officials steamover mask-reuse claim

Health officials yesterday took pro-Beijing lawmaker Ann Chiang Lai-wan to task over her claim that one can reuse a face mask after putting it through steam.

The Centre for Health Protection said in its Facebook page that people should "absolutely not reuse" a face mask after "disinfection."

Featuring a graphic showing a mask in a pan of boiling water, the post said: "dispose of surgical mask after using, do not steam it and reuse."

It said that used surgical masks are contaminated with pathogens and must be dumped in a covered bin.

"The efficacy of face masks would be affected when they are wet. Don't easily believe online messages from unreliable sources," it wrote.

Chiang, a member of Alliance for the Betterment and Progress of Hong Kong, hit back on her Facebook page yesterday.

"The Centre for Health Protection stated that masks can only be used once, which I agree is the best way, but I would like to point out that according to the documents, there are three layers to a general mask, the main one is the middle layer, which is used to filter viruses," she said.

"The material of the middle layer of general masks is made of polypropylene fibers. The melting point of polypropylene fibers is as high as 167 degrees Celsius. The temperature for usage is between minus 30 degrees and 140 degrees Celsius. [They are] heat resistant and steam sterilizable," she said.

She quoted National Health Commission expert Li Lanjuan as saying that the coronavirus can be killed at above 56 degrees, while top microbiologist Yuen Kwok-yung of the University of Hong Kong said the virus could easily die at 30 degrees.

"The approach of using 100 degrees Celsius water to steam and kill the virus is not unworkable," she wrote.

Pro-democracy lawmakers expressed shock yesterday after Chiang posted a one-minute video on Wednesday night demonstrating how to steam face masks so they can be reused.

Democrat Roy Kwong Chun-yu said Chiang even told members of the Legislative Council's health services panel, which she chairs, that she was currently wearing a mask that she had steamed.

Pierre Chan, the medical sector lawmaker, and a medical professional, said it is simply a "horrible" idea and appealed to people not to take up the suggestion.

charlotte.luo@singtaonewscorp.com