WASH AND GO

Ally reusable face mask, £15, chooseally.com WASHABLE up to 20 times. NUMBER OF COLONIES: 13 PERCENTAGE BLOCKED: 80 VERDICT: Four layers but it let through 20 per cent of droplets. To wash, soak at 60c to 80c for ten minutes, rinse and dry overnight.

Putting masks to the test: Professor Val Edwards- Jones