Universiti Malaya occupational and public health expert Prof Dr Victor Hoe said reusable fabric masks would not be able to filter out micro-dust and bacteria, like surgical masks do.
“The three-ply mask contains a high-level static filtration non-woven middle layer which effectively blocks out micro-dust and bacteria – which is not present in fabric masks.
“Furthermore, the pore size in fabric masks also varies, depending on the type of fabric,” he said when contacted.
Prof Hoe said wearing fabric masks “will not be useful” to prevent one from contracting the virus from others.
“It may offer a false sense of security that you are protected. It will not be able to protect you against getting infection from others.
“However, if you are sick, wearing the fabric mask will help you to avoid spreading the infection to others. If you want to reuse the fabric mask, then it needs to be cleaned properly first,” he said.
Respiratory physician Dr Helmy Haja Mydin said fabric masks should not be worn by medical personnel, and that healthy asymptomatic citizens need not wear masks in the first place.
“Fabric masks for hospital staff may not be hygienic and there is a risk of cross-infection,” he said, citing a UNSW Sydney study in 2015 that found that respiratory infection was higher among healthcare workers who used cloth masks.
“The moisture retention, the reuse of cloth masks and poor filtration may result in an increased risk of infection,” he said.
Malaysian Public Health Medicine Specialist Association president Datuk Dr Zainal Ariffin Omar said: “While fabric masks do not offer protection against the Covid-19 virus, it may serve as an alternative should there be a surgical mask shortage.”
“There is no need to wear a mask unless you are a frontliner or if you have symptoms.
“However, frontliners can only use fabric masks if there really are no other masks available, but they should wear an extra face shield,” he said.
A 2013 study by Cambridge University in Britain showed that homemade masks should be used only as a last resort if the normal three-ply masks were unavailable.
“Our findings suggest that a homemade mask should only be considered as a last resort to prevent droplet transmission from infected individuals, but it would be better than no protection,” the researchers concluded.
The study found that while materials such as silk, linen and cotton blocked out some microbes, surgical masks still had the best filtration efficiency.
This was followed by vacuum cleaner bags and tea towels, though their material was too stiff and thick to be used as masks.
However, the researchers added, homemade masks “would provide the wearers little protection from microorganisms from other persons who are infected with respiratory diseases”.
“We would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols,” the researchers said.
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