Scientists have issued a warning to women about using talcum powder - they say it increases their risk of developing ovarian cancer.
According to researchers from Harvard Medical School, particles in the powder when applied to the genitals can travel to the ovaries and trigger a process of inflammation that allows cancer cells to flourish.
Other research has previously raised concerns over the use of talcum powder but this new study suggests women who use it are 40% more likely to develop ovarian cancer - a much greater risk than first thought.
The researchers studied more than 3,000 women and found using talc merely once a week raised the risk of cancer by 36% rising to 41% for those applying powder every day.
The study used data on 1,175 cases and 1,202 controls from a New England-based case-control study and 210 cases and 600 controls from the prospective Nurses' Health Study.
According to Dr. Maggie Gates, who led the study, until more research is done women should avoid using talcum powder in the genital area.
The study also revealed that the risks were greater still for those with a certain genetic profile - women carrying a gene called glutathione S-transferase M1, or GSTM1, but lacking a gene called glutathione S-transferase T1 ( GSTT1), were nearly three times as likely to develop tumours.
Around one in ten Caucasian women are thought to have this genetic profile, putting them at sharply increased risk.
Talcum powder is made from a soft mineral called hydrous magnesium silicate, which is crushed, dried and milled to produce powder which is in cosmetic products used by millions.
Some experts suggest it has chemical similarities to asbestos, which can cause a deadly form of lung cancer.