The best and worst face masks for keeping germs out have been rated by consumer champion Which? - with an Adidas coverings sold by ASOS, Next and Sports Direct coming last.
The Adidas face mask - which costs £17 for a pack of three - filtered out only a third of harmful particles like coronavirus, according to researchers.
Other coverings that scored poorly in the Which? test include the Vita Shield face mask - priced at £9.99 for a pack of three - which dropped from 60% filtration on first use to 38% after five washes.
The third worst rated was a face covering from Next which scored two out of five stars for filtration efficiency and costs £6.
Overall, Which? found some of the face coverings with high filtration claims on the packet did not live up to expectations.
It also found a further seven of the 12 masks tested had poor packaging instructions that failed to provide key information.
On the other end of the table, the best face covering tested was the Airpop Pocket at £24.99 for four, direct from Airpop or Amazon, which was found to block more than 99% of potentially harmful bacterial particles.
The covering - classed a Which? Best Buy - is made from similar materials to disposable masks and was described by the consumer champion as doing a “superb job of filtration”.
But it does point out that this mask is “semi-reusable” meaning it can only be washed and reused a set number of times.
Superdrug was also awarded Which? Best Buy status and came second overall for its reusable face covering, priced at £4.99 for three masks.
Masks from The Big Silk, which cost £16.90 each, and Marks & Spencer, priced at £9.50 for five, also got the same accolade due to them having a “balance between filtration and breathability”.
Testers found them “comfortable to wear” as well, according to the consumer champion.
Which? tested a range of face coverings and masks sold by pharmacy chains, supermarkets, high street stores and online retailers for its research.
Scientists looked at how well they filtered particles, how breathable they were, and how they fared after multiple washes.
Harry Rose, editor of Which? magazine, said: “Face coverings not only need to be durable and comfortable, but also provide effective filtration in order to keep us and others safe.
“Our tests show there is still work to be done to improve the quality of face coverings.
“While the best reusable face coverings can be just as effective as a disposable mask, there are still too many that fall short of the mark.
Adidas told Which? its mask was designed early on in the pandemic, before there were defined performance criteria.
A spokesperson said: “Our face cover was designed for the general public and is not medically graded.
"It can help limit the spread of droplets, to help protect others from transmissible germs.
"This is outlined clearly on the consumer-facing product communications.
"There was not an industry standard for non-medical face coverings at the time of design, but it was comprehensively tested together with our development partners against Adidas’ performance criteria to ensure safe breathability and comfort for wearers.”
Vita Group said it was “surprised and disappointed” by the results.
A spokesperson said: "The Vita Group stands behind the test results rigorously generated over the last 12 months by Centexbel, a world-renowned independent accredited test centre.
"Their results bear no relation to the results obtained by Which?.
"Extensive tests have taken place across the UK and Europe over the past year with the Vita Shield recording 99% filtration efficiency and 99% filtration efficiency after 10 wash cycles."
The Mirror has contacted Next for comment.
12 best and worst rated face masks, according to Which?
The overall score takes into account filtration efficiency, breathability, cleaning, harness strength, instructions and what its testers thought overall.
- Adidas Airpop pocket mask - £24.99 for four (94% overall test score)
- Superdrug reusable cotton face covering - £4.99 for three (86% overall test score)
- Wise Protec antiviral adult face covering - £10 for one (86% overall test score)
- The Big Silk face mask - £16.90 for one (85% overall test score)
- M&S reusable jersey face covering - £9.50 for five (82% overall test score)(94% overall test score)
- Lloyds Pharmacy reusable face covering - £4.99 for two (74% overall test score)
- Tu adult non-medical face covering - £6 for three (72% overall test score)
- Alvita semi-reusable barrier mask - £7 for two (69% overall test score)
- Boots adult reusable face mask - £10 for two (67% overall test score)
- Next plain black face covering - £6 for one (56% overall test score)
- Vita Shield face covering - £9.99 for three (39% overall test score)
- Adidas face covering - £17 for three (38% overall test score)
