Proper fit of face masks is more important than material, says study

In order to provide best protection against COVID-19, fit of a face mask is more important in some cases than material it is me of, according to a study which suggests new ways for manufacturers to test effectiveness of masks.

While studies over course of COVID-19 pandemic have shown importance of wearing face masks in slowing spre of coronavirus, researchers from University of Cambridge in UK said re is a lack of understanding about role that good fit plays in ensuring ir effectiveness.

study, published in journal PLoS ONE, conducted a series of different fit tests and found that when a high-performance facemasks -- such as an N95 mask -- is t properly fitted, it performs better than a cloth mask.

According to researchers, mir differences in facial features, such as amount of fat under skin, make significant differences in how well a mask fits.

y said fit-check routine used in many healthcare settings has high failure rates, as mir leaks may be difficult or impossible to detect by wearer.

scientists hope ir findings will help develop new fit tests that are quick and reliable in case of future public health emergencies.

"We kw that unless re is a good seal between mask and wearer's face, many aerosols and droplets will leak through top and sides of mask, as many people who wear glasses will be well aware of," said study's first author Eugenia O'Kelly from University of Cambridge.

In study, seven participants first evaluated N95 and KN95 masks by performing a fit check.

participants n underwent quantitative fit testing -- which uses a particle counter to measure concentration of particles inside and outside mask -- while wearing N95 and KN95 masks, surgical masks, and fabric masks.

According to scientists, N95 masks offered higher degrees of protection than or categories of masks tested.

However, y said most N95 masks failed to fit participants equately.

scientists found that when fitted properly, N95 masks filtered more than 95 per cent of airborne particles, offering superior protection.

But y said in some cases, poorly-fitted N95 masks were only comparable with surgical or cloth masks.

"It's t eugh to assume that any single N95 model will fit majority of a population. most widely-fitting mask we looked at, 8511 N95, fit only three out of seven participants in our study," said O'Kelly.

researchers said width of flange of mask -- area of material which comes in contact with skin -- may be a critical feature to fit.

Masks which fit greatest number of participants tended to have wider, more flexible flanges around border, y ded.

Small facial differences also have a significant impact on quantitative fit, study ted.

"Fitting face perfectly is a difficult technical challenge and, as our research showed, small differences such as a centimetre wider se or slightly fuller cheeks can make or break fit of a mask," said O'Kelly.

scientists believe ir results will be of use for those who are working on new techlogies and programmes to assess fit.

y hope findings would bring attention to importance of fit in clinical-gre masks, especially if such masks are to be widely used by public.

(Im credit: AP)