A HOLE IN THE LOGIC...

Durable neoprene respiratory mask with valve, £3.99, chemist-4-u.com

Washable and made from quick-drying, hypoallergenic fabric. Claimed to be effective against air pollution, pollen and bacteria. NUMBER OF COLONIES: 30 PERCENTAGE BLOCKED: 54 VERDICT: Valve masks have become popular — even rishi sunak has one — but while they are great at blocking dust and pollution and keep your face less humid, those around you aren’t protected because your germs are breathed out through the valve hole. the second worst-performing mask in our tests.