Has your cloth mask faded with multiple washes? Don't throw it away, it still works

Research suggests that regular washing and drying of reusable cloth masks does not reduce their ability to filter out viral particles

Does a reusable cloth mask, discoloured from multiple washes, become ineffective in protection against Covid-19? A recent study says no.

Researchers at University of Colorado Boulder suggest that regular washing and drying of reusable cloth masks does not hinder their ability to filter out viral particles.

Marina Vance, one of the lead authors of the study, said “That cotton mask that you have been washing, drying and reusing? It's probably still fine, don't throw it away."

Also read: Pandemic mask mountain sets new recycling challenge

Researchers tested the masks using real-life conditions like high humidity levels and temperatures to mimic the impact of human breathing. While the cotton fibers started falling apart over time after repeated washing and drying, the researchers found that did not significantly affect the cloth’s filtration efficiency.

The only noticeable change was that inhalation resistance slightly increased meaning that the mask may feel a bit more difficult to breathe through after some wear and tear.

The study, published in the journal Aerosol and Air Quality Research, also confirms previous research that layering a cotton mask on top of a surgical mask, properly fitted on one's face, provides more protection than cloth alone.

Measuring how well the mask filtered air being breathed in, this study found that the cotton cloth masks filtered out up to 23 per cent of the smallest particle size (0.3 microns) on which the virus can travel.

The research suggested that in comparison, surgical masks filtered out between 42-88 per cent of the tiny particles and cotton masks on top of surgical masks reached close to 40 per cent filtration efficiency. KN95 and N95 masks unsurprisingly performed the best, filtering out 83-99 per cent of these particles.

Check out DH's latest videos