Cloth Masks And COVID-19 - M.A.Aleem BMJ 2020;369:m1422

BMJ 

British Medical Journal 

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Covid-19: What is the evidence for cloth masks?

BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m1422 (Published 07 April 2020)

Cite this as: BMJ 2020;369:m1422

 

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Re: Covid-19: What is the evidence for cloth masks?

Dear Editor

Cloth Masks And COVID-19

It is found that homemade masks had filtration rates ranging from 1% to 79%—compared with 97% for N95 masks and 62% to 65% for surgical masks.

The best-performing face masks were made of two layers of heavyweight “quilter’s cotton” with a thread count of 180 or more. Also performing well were fabrics with thicker thread and tight weave, such as batiks. Double-layer masks made with a cotton outer layer and a flannel inner layer also did well.

Single-layer masks or double-layer masks made of lightweight cotton didn’t perform well.

It’s unclear how often masks need to be washed. But experts say if you are wearing them for brief periods, wash them with a dilute bleach solution or soap and water weekly, at minimum.

 Cloth masks can be washed with other laundry. If you’re wearing them for extended periods—like grocery-store employees do—clean them daily. Don’t share masks, even with family members.

Experts say masks can’t be a substitute for other more effective virus-prevention strategies such as social distancing in preventing the spread of COVID-19.

Competing interests: No competing interests

10 April 2020

M.A. Aleem

Emeritus Professor of Neurology * Visiting Specialist in Neurology ** Consultant Neurologist ***

The Tamilnadu Dr.M.G.R. Medical University * Dhanalakshami Srinivasan Medical College ** ABC Hospital ***

Chennai 600032* Perambalure 621212** Trichy 620018*** Tamilnadu India

@drmaaleem