PETALING JAYA: As more contagious Covid-19 strains emerge, including the Delta variant, doctors are reminding the public about the importance of ensuring the effectiveness of their face masks.

       Dean of the Faculty of Pharmaceutical Sciences at USCI University Assoc Prof Dr Mogana Sundari Rajagopal said all medical or surgical face mask manufacturers in Malaysia are required to hold an ISO 13485 certification and be registered by the Medical Device Authority (MDA).

       “The MDA helps to monitor the role of the medical device manufacturer and all these manufacturers have to register their establishments along with their products,” she said.

       Each country, she added, has its own certification standard for each type of masks.

       “For example, Europe uses the EN 14683 or ASTM F2100 standard for medical or surgical masks, whereas China uses the YY 0469 standard.

       “Although the standards vary a little in each country, they are, however, broadly similar,” she said.

       The public, added Dr Mogana, must ensure that face masks are regulated under the international standard such as EN or ASTM by authorised bodies such as Sirim Bhd, SGS Malaysia and others.

       “Unfortunately, many manufacturers and distributors are not registered and are selling face masks that are not properly regulated,” she said.

       Dr Mogana said to avoid purchasing counterfeits, there were certain ways to identify the quality of a medical or surgical face mask, adding that those carrying the ASTM (American Society for Testing and Materials) or EN (European Standard) rating met international standards and requirements.

       “While surgical masks, N95 masks and other medical-grade personal protective equipment have long had established standards in place, this new standard for everyday masks is a first and is meant to provide a benchmark for both manufacturers and the public,” she said.

       Consumers, she said, could simply look for ASTM Level 1, 2 or 3 rating on the face mask package before making a purchase.

       However, not all face masks are ASTM-rated.

       “It is worth the effort to find face masks that carry the ASTM rating and to be sure you’re getting the proper level of protection,” she said, adding that the people are often confused about N95 and medical-grade face masks such as surgical face masks.

       The N95 or KN95 masks are categorised as respirators.

       She said for adequate protection against the coronaviirus, which is about 0.1 micron in size, a medical or surgical face mask in compliance with EN Type IIR or ASTM Level 3 with good filtration is highly recommended.

       Dr Mogana said while certain manufacturers produced masks in a variety of colours and patterns, there was, however, no colour coding for surgical masks.

       “Colour, writing or printing on masks should be avoided as per studies done.

       “Dyes should be selected according to internationally accepted industry standards to protect our health and the environment.

       “An international consensus concerning face mask colour based on their impact on health should be investigated and determined,” she said.

       “Certain dyes are toxic and persistent and have both short and long-term negative impact on human health, fauna and flora,” she added.

       To choose the right face mask, Dr Mogana recommended using masks manufactured by companies with a Medical Device Quality Management System ISO 13485:2016 certificate.

       Assoc Prof Dr Kyu Kyu Win, a microbiology lecturer at the Faculty of Medicine and Health Sciences at USCI University, said the combination of a fabric mask and surgical mask could improve fit and filtration of the particles.

       “Wear the disposable medical or surgical face mask underneath and a cloth mask on top to have a better fit and extra protection. The cloth mask can also be combined with a fitter or brace.

       “Knot and tuck ear loops of a three-ply face mask where they join the edge of the mask, fold and tuck the unneeded material under the edges.

       “However, the surgical or medical mask should not be layered with the same type of mask as this combination doesn’t improve fit. The N95 mask is meant to be used alone,” she said.

       She said the World Health Organisation had recommended a four-hour lifespan for surgical masks.

       Dr Hean Ooi, who is vice-director of the International Centre at China Medical University Hospital, said wearing a face shield alone is not only against the existing standard operating procedure, it also does not provide a good fitting.

       He said the performance of masks was tested by assessing their bacterial filtration efficiency (for bacteria more than three microns in size), particle filtration efficiency (of less than 0.1-micron particles) and so on.

       He said surgical mask standards had higher requirements for capturing virus-sized particles of more than 98%.

       “For respirators such as the N95 and KN95, use multiple layers of synthetic material to protect yourself from particles.

       “As their names suggest, both must filter out 95% of particles that are 0.3 microns in size or larger,” he said.

       Dr Ooi advised the public to look for a medical or surgical face mask that complied with the EN or ASTM standard required for a face mask.

       “Plus, a good face mask should be constructed with three layers unlike those cheap face masks which have only one layer,” he said.

       He added that respirators such as the N95 and KN95 or KF 94 were not encouraged for daily use as it could cause breathing difficulties if worn for up to eight hours a day. — Bernama