Dr Marcus Sim.

KUCHING:In general, evidence appears to show that fabric face masks or face coverings are likely better than no mask at all, says medical practitioner Dr Marcus Sim.

He said that these fabric face masks could be useful in reducing the spread of Covid-19 in situations where individuals are unable to practise physical distancing.

“This is especially true when considering outward spread (from oneself to others), hence the emphasis on wearing masks not to just protect ourselves, but those vulnerable around us,” he told New Sarawak Tribune.

He added that while fabric masks would not fully stop all particles, it could certainly reduce the directional speed and the number of virus-laden particles introduced into the air, which in turn reduces the number of surfaces exposed to later be transmitted by touch.

At the same time, he emphasised that face masks and coverings, irrespective of type, were interventions that must go in tandem with other precautionary measures such as physical distancing and good hand hygiene. 

“These masks should not lead people into a false sense of security as it is important to continue to maintain physical distancing where still possible, regardless of the face mask you have on,” said Dr Sim, who works in the United Kingdom.

Paying attention to materials

He said that the term ‘fabric mask’ or ‘face covering’ was a bit of a catch-all term, adding that not all fabric masks were made the same.

“For example, there are several other important factors worth considering, such as the type of material used and the fit of the mask.” 

He said that a recent pre-print study from the Oxford Leverhulme Centre for Demographic Science had raised several important points specifically about the material of fabric masks.

Citing the study, Dr Sim said that tightly woven fabrics (higher thread count cotton) were essentially better than looser materials, and two layers or more were better than a single layer of fabric.

He pointed out that the World Health Organisation’s (WHO) recommendation was for three layers.

“In addition, hybrid layers with different materials –for example, cotton-silk, cotton-flannel, cotton-chiffon – are better than two layers of identical material.

“A proper fit when the mask is worn is also crucial as the effectiveness of all masks (fabric, surgical, or N95) is seriously reduced when a gap is introduced.”

Fabric masks, surgical masks, and respirators

Dr Sim noted that the types of face masks available on the market were typically divided into fabric masks, surgical masks, and respirators (such as N95).

He said that, generally, fabric masks were suggested for low-risk individuals and the general public, especially in the context of limited surgical mask resources.

However, he noted that many fabric masks on the market had been made with an emphasis on fashion or aesthetics.

“The ideal fabric mask should have a minimum of three layers with an inner hydrophilic material and two outer hydrophobic layers.”

Meanwhile, he said that surgical face masks, which were used as personal protective equipment (PPE), should generally be reserved for healthcare workers or higher-risk individuals in situations where there was a shortage of vital PPE.

“Similarly, respirators like the N95 masks are of little additional benefit to the public as they are not usually exposed to aerosol generating procedures outside of a hospital setting.

“In addition to being a limited resource for healthcare workers, these masks depend on an airtight seal that needs to be individually tested for in order to be effective.”

Use of face masks among children

Young children should not wear face masks due to risk of them choking or suffocating, advised Dr Sim.

Citing a warning by the Centres for Disease Control and Prevention, he said, “Masks should not be worn by children under the age of two or anyone who has trouble breathing, is unconscious, incapacitated, or otherwise unable to remove the mask without assistance.”