[EXPERT REACTION] Do cloth face masks work against COVID-19?

Cloth face masks - CDC

With the shortage of N95 and surgical face masks, cloth coverings are probably the next best option. Health authorities including the Centers for Disease Control and Preventions (CDC) have been encouraging people to make cloth face masks at home to guard against the spread of the coronavirus. We asked experts:

Do cloth face masks work against COVID-19?”


Dr Vinod RMT Balasubramaniam, Virologist & Senior Lecturer at Jeffrey Cheah School of Medicine & Health Sciences, Monash University Malaysia, said:

“The idea behind this is actually to reduce the public from actually hoarding the supply of face masks (2 ply surgical masks or N95 respirator) in the market and off the shelf. Since frontline/medical personnel need it more. Cloth face coverings fashioned from household items or made at home from common materials at low cost can be used as an additional, voluntary public health measure. It may slow down the transmission, however, they are not as effective as the one being used in hospitals (both the surgical masks or N95 respirator).

“There are a few precautions that should be adhered to if we are to use cloth face masks:

  • 1. They should be routinely washed depending on the frequency of use.
  • 2. Individuals should be careful not to touch their eyes, nose, and mouth when removing their face covering and wash hands immediately after removing.
  • 3. If it is a DIY cloth face mask, use tightly woven cotton, such as quilting fabric or cotton sheets. T-shirt fabric will also work.”

Prof Dr Liong Min Tze, Microbiologist & Associate Professor at the School of Industrial Technology, Universiti Sains Malaysia, said:

“As mentioned above, frontliners would definitely need a mask, but not a cloth mask, a proper one such as N95, as this is designed to protect against very small particles. This video may provide some explanation on this. Also, as mentioned above, the way to remove a mask is also important, plus the reduced tendency to adjust the mask or touch the mask is crucial. We do see people having an increased tendency to touch the mask and face as compared to a naked face.

“As for the general public, a mask serves the best protection for others instead of ourselves. Wearing a mask prevents our own fluid from spreading to others and the environment (including surfaces) and this is typically important since 30% of COVID-19 patients do not have symptoms. We may carry the virus and unaware of that thus spread further. Thus, it should become our responsibility not to spread to others and wear a mask for this reason. 

“Cloth masks and surgical masks cannot be used for viruses. They are thin, do not have a full closure with exposed areas on the sides and could absorb fluid. It can offer some protection although limited, of direct transfer of the virus to our respiratory entrances such as mouth and nose, such as someone directly coughing at us. That is also, provided if we remove it very soon afterwards (in a correct way) and dispose it correctly. However, if we were to wear those for hours, any absorbed virus can be transferred to our mouth and nose too. Recent evidence has shown that SARS-CoV-2 can survive on printing and tissue papers under 3 hours, wood and cloth for over 1 day but less than 2 days.”

Datuk Dr Amar Singh HSS, Senior Consultant Paediatrician, said:

“There have been some fake graphics circulating suggesting that cloth masks are useless against viruses. It is possible that the authors of those graphics have a vested interest in selling medical masks. Some kind individuals have summarised some of the studies done on DIY (homemade) masks protection against coronavirus; one here and another here. The data suggest that the surgical mask was three times more effective in blocking transmission than homemade masks. Homemade masks were not as good with aerosol transmission and do not fit as well, especially for children. However they can filter ~ 50-60 per cent of virus-sized particles and last for at least 3 hours (a cotton handkerchief filtered 28 per cent). Cloth masks made of cotton t-shirts or dish cloth (‘tea cloth’) were the most useful. The quality of these DIY masks can be improved (see below on making them).

“Some good work done on real-time imaging of human exhaled airflows shows that when two persons are having a normal conversation, their exhalation airflows overlap and interact (as we well know). The airflow is spread even further when someone is coughing, sneezing or laughing.

“We are all also well aware, from a number of studies, that a significant proportion of persons (20-50 per cent) infected with the coronavirus are asymptomatic or pre-symptomatic. So we have to assume and live as if every ‘well’ person we meet is infected. Hence any mask used is better than no protection (a ‘last resort’) and may decrease viral exposure and infection risk. In addition, using a mask protects others from our respiratory droplets. Remember that cloth masks are not recommended for healthcare professionals as they are in a much higher risk environment.”

Disclaimer: These comments were complied to provide journalists with a range of expert perspectives on the subject. The views expressed here are the personal opinions of the experts. They do not necessarily reflect the views of the Science Media Centre or any other organisation unless specifically stated. 
Bionotes of expert

Datuk Dr Amar-Singh HSS is a senior Consultant Paediatrician. He is an individual member of the Malaysian Health Coalition. He has served at the Hospital Raja Permaisuri Bainun, Ipoh for more than 35 years prior to retiring as Head of the Paediatric Department and Head of the Clinical Research Centre Perak in 2018. During his tenure, he was responsible for Paediatric & Research services in the state of Perak. Dr Amar also sits as the Advisor of the National Early Childhood Intervention Council. He is a Senior Fellow of the Galen Centre for Health and Social Policy and a recipient of the Outstanding Asian Paediatrician Award 2012 as well as 2016 SENIA Advocacy Award. As a senior paediatrician, he has a long standing interest in health and development issues pertaining to children with disability and facing abuse, as well as disadvantaged & marginalised communities (particularly in the Orang Asli/Indigenous People). He often writes on the development of the health sector and has a series of editorials on these and other health issues in several Malaysian media outlets.

Prof Dr Liong Min Tze obtained her PhD in Food Microbiology and Safety from Victoria University, Melbourne, Australia in 2006 before joining Universiti Sains Malaysia. Her research emphasizes on probiotics, prebiotics, nutraceuticals and the utilization of agricultural wastes for the production of by-products. Dr Liong has published over 80 papers in international peer-reviewed journals and she is also on the Editorial Board of several international journals and has reviewed over 100 journal manuscripts for reputable international journals. She has also delivered keynote and plenary lectures both nationally and internationally. Dr Liong was named one of the three top young women scientists in Malaysia (2007) by FWIS L’Oreal-UNESCO. She was also awarded the IAP Young Scientist, to represent Malaysia at the World Science Forum in Budapest to pitch for changes in science policies in the Hungarian Parliament (2015). In 2016, Dr Liong was named as one of the Top Research Scientist Malaysia, awarded by Academy of Sciences Malaysia (ASM).

Dr Vinod RMT Balasubramaniam graduated from Asian Institute of Medicine, Science and Technology (AIMST) majoring in Biotechnology in 2007. During this period, he managed to publish several papers on plant genetic engineering, especially on genetically engineered orchids which have resistance towards fungus. In 2008, he worked as a research assistant with Associate Professor Sharifah Syed Hassan in her newly formed infectious disease laboratory in Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia. He embarked on his PhD course working on the various host cellular genes infected with Avian Influenza Virus H5N1 and their protein-protein interactions with viral genes. Graduated with merit in 2014, he continued to work as a post-doctoral fellow before joining Professor Adolfo Garcia-Sastre’s laboratory in Mount Sinai hospital New York, which is one of the leading Influenza research laboratory in the world. He has co-authored various publications (Cell Host Microbe, Nature Microbiology, Plos Pathogens) on various aspects of host response towards different types of viruses. 

Here is a guideline by CDC on how to wear a cloth face covering: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html

**All previous posts about COVID-19 here: https://sciencemediacentremalaysia.com/tag/covid-19/

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