Doctors in the UAE have said residents should be cautious when buying fashionable face masks as some did little to protect against Covid-19 infections.
Medical experts said consumers must ensure that more decorative masks now on sale were equally “effective at suppressing transmission”.
Thicker, more densely woven fabrics with a high thread count are generally recommended by health professionals.
By contrast, materials that appear transparent when held up to the light, or masks fashioned from loose-fitting bandannas are not seen as effective.
Speaking to The National, Dr Ravi Arora, internal medicine specialist at NMC Specialty Hospital in Abu Dhabi, also said the use of more durable cloth face coverings could help overcome the risk of a global shortage of surgical masks.
“Cloth masks are cheap, simple to make and can be re-used,” he said.
“For them to be effective, the cloth mask should include multiple layers of fabric.
“Thicker, more densely woven cotton fabrics are best, such as quilting cotton or cotton sheets.
“When you hold the fabric up to the light, the fewer tiny holes you can see the better it will work to filter droplets."
The warnings from medics came as some retailers and websites have begun selling a variety of face coverings with more eye-catching designs.
Masks depicting superheroes aimed at children are now widely available, along with a multitude of popular comic strip characters and movie themes.
Doctors said the “health, safety and functionality” of masks must remain a priority for consumers when considering what to buy.
Experts also reminded members of the public that face coverings were "not a substitute for social distancing", especially in areas where transmission was high.
“On reviewing what the WHO and CDC recommend, cloth masks are a good option for people to wear in a public setting, such as going for a walk or to the supermarket," said Dr Osman El-labban, a family medicine consultant at Al Zahra Hospital in Dubai.
"Studies have shown that tightly woven, multi-layered cotton materials perform better and limit transmission of virus.
“If you are going to a hospital setting or are in close contact with strangers, I recommend you opt the surgical face mask."
The wearing of face masks has been recommended by governments and health authorities around the world to help minimise the risk of pre-symptomatic and asymptomatic spread of Covid-19.
Using masks in public became mandatory in the UAE on April 4, although many residents had already adopted wearing them by mid-March.
A recent study by the Wake Forest Institute for Regenerative Medicine in the US found the effectiveness of cloth masks varied widely.
Research teams investigated which household materials “best removed particles of 0.3 to 1.0 microns in diameter”, the size of many viruses and bacteria.
The best-performing designs were constructed of double layered vacuum cleaner bags and heavyweight quilter’s cotton – with a thread count of 180 or more.
A multi-layered mask with a “simple cotton outer layer and an inner layer of flannel” also performed well.
The less effective masks were single-layered or double-layered designs of lower quality, lightweight cotton.
On Wednesday, no new Covid-19 deaths were reported in the UAE.
Sheikh Mohamed bin Zayed, Crown Prince of Abu Dhabi, praised medical staff for their efforts to contain the virus but said further work to tackle the infection remained ongoing.
