Scientists have proved what wool fans know – merino wool is the best fabric to beat the perma-stink:
When Rachel McQueen’s husband was training for a marathon, she noticed the smell emanating from his running clothes was much stronger and lingered longer in his polyester tops than if he had run in a merino wool top.
“I was repulsed,” said the textile scientist. Even freshly laundered, her husband’s polyester running tops still stunk. “The smell was as strong as if they had just been worn and I realized you can get perma-stink.”
McQueen, who has made it her mission to find the causes of perma-stink, conducted a study in which she compared the relationship between body odour and different fabrics. She had male volunteers wear test T-shirts, which had swatches of polyester, cotton and merino wool stitched to the underarm regions. They wore the shirts for two consecutive days and then the swatches were removed for testing. Smell tests using sensors were conducted on each fabric after one day, seven days and 28 days of storage.
“Polyester was by the far the most odorous,” she said. “Wool was the least smelly, and cotton was low to medium.”
The chemical odour-binding sites within fibres are key in determining the stink level, so McQueen focused her attention on the chemical makeup of fibres and how it affects odour retention.
She found that wool and cotton are hydrophilic and absorb more water than polyester.
“Wool is a fibre with an amorphous structure,” explained McQueen. “It has open spaces and is more porous than a synthetic fibre, so it can absorb a lot of sweat.”
That means that if odour molecules are trapped within wool or cotton, we can’t smell them as readily as we can with polyester, which has fewer chemical odour-binding sites.
To keep perma-stink at bay while being active, McQueen suggests the following:
Choose fabrics that have higher cotton or wool content.
“People are generally attuned to their own body odour. If you’re concerned, go with natural fibres,” said McQueen.
Wool went out of fashion, but the development of machine washable merino brought it back and its popularity has been enhanced by its environmental credentials.
Concerns over tiny particles of plastic from synthetic clothing getting to the ocean in washing water is turning the tide back to natural fabrics.
It’s a rare day when I don’t wear at least one layer of merino, it’s my preferred choice for exercising and I always wear it when travelling.
It’s warm when it’s cold, cool when it’s hot and, as science has proved, it’s the best to beat the perma-stink.