Using talcum powder does not increase the risk of ovarian cancer, according to a major study.
Controversy has surrounded the use of the powder on women's genitals since the 1970s, after the talc mineral was discovered to be contaminated with asbestos – which is known to cause cancer.
But a review of four US studies of more than a quarter of a million women has now declared there is 'no significant association' between the powder and cancer.
Scientists praised the study, calling it 'robust' and 'very well conducted', and said it was reassuring for women worried about using talcum powder.
It comes after Johnson & Johnson was in 2018 ordered to pay £3.6billion ($4.7bn) in compensation to 22 women who won a US lawsuit in which they claimed the firm's baby powder gave them cancer.
The company also recalled 33,000 bottles of talc in the US in October 2019 because regulators found traces of asbestos in it.
Johnson & Johnson, which famously makes talc baby powder, was sued for a total of £3.6billion in 2018 by 22 women in the US who claimed the product had given the ovarian cancer. It has since won court cases against other women alleging the same thing
Krystal Kim, 53, is one of 22 women who sued Johnson & Johnson over claims using talcum powder gave them ovarian cancer
A team from the US National Institute of Environmental Health Science in North Carolina combined and analysed the results of four studies.
Some 252,745 women were enrolled in the studies between 1976 and 2009 and had their health and talcum powder use tracked for around 11 years.
More than a third of them (38 per cent) said they used the powder on their genitals.
Women have done this for decades to absorb moisture and odours, the scientists said.
The study found, among women who did use talcum powder, there were 61 cases of ovarian cancer per 100,000 women over an 11-year period.
Among women who had never used talcum powder this rate was 55 per 100,000, it found.
Although the number was higher, the rate of cancer rose only from 0.055 per cent to 0.061 per cent, which was deemed too small to be a solid link – it may have been down to chance.
Talcum powder is made of finely ground talc, a mineral which forms underground as a clay-like rock.
Talc is often mined from the same place as asbestos, a mineral known to cause lung disease.
While talc is used for the skin, thanks to its softness and moisture-absorbing properties, asbestos was used for insulation.
Non-contaminated talc is completely safe. But if it is tainted with asbestos, there is a risk it could be damaging to health. Tests have in the past found traces of asbestos in talcum powder products.
Asbestos is made up of six minerals that form together as tiny crystallised fibres. The minerals on their own aren't dangerous, but together they are a recognised cause of cancer.
About eight out of 10 people with mesothelioma – a type of lung cancer – have been exposed to asbestos. When asbestos fibres are breathed in, they travel to the ends of small air passages and reach the membranes of the thorax and