Towels are one of the most frequently used items in our daily routines, soaking up our residual impurities and dead skin cells at least once a day for many of us. Given this heavy-duty role, it begs the question of how much our towels can handle before they become too filthy to use without returning all that grime back to us.
A 2023 study based on a sample of 2,200 Brits estimates that a third of UK residents only wash their shower towels once every three months, 8% do so twice a year, and 3% only freshen up their towels once every year - significantly less than other parts of the world, with an Indian paper evidencing 40% of their population washes theirs once a week.
When freshly laundered, a towel can contain around 190,000 counts of bacteria, a figure which increases to 17 million after just one day of use, and skyrockets to as high as 94 million after a week.
And these microbes aren't just originating from our own skin, but also include airborne fungi and bacteria that can settle on towel fibres while they are hanging up, or be left over from the water we used to wash them before use.
More bad news: leaving our towels to hang in the toilet causes them to absorb a light dusting of bacteria from your bodily waste every time you flush.
Elizabeth Scott, a professor of biology and co-director of the Simmons University Center for Hygiene and Health in Home and Community in Boston, explains that "gastroenteric infections resulting from Salmonella, Norovirus and E. coli are all transmissible through towels", reports the BBC, and human papillomaviruses, a common cause of warts and verrucae, can also be spread through shared towels.
So, how long should you wait before washing your towels to avoid health issues? Professor Scott suggests doing the washing once a week, although context does matter: "It doesn't make a whole lot of sense because if someone is sick, they've got vomiting and diarrhoea".
"They need to have their own towel and those towels need to be laundered on a daily basis. That's what we call targeted hygiene, you deal with the risk as it occurs", she explains.
She adds that towels should be washed for longer than most fabrics, and in hotter water (40-60C). Adding enzymes or bleach also helps combating microbes in towels, she says.
"Towels are a relatively small component, but there are definite risks with towels and it's easy to deal with that."
