Australian women are being advised to reconsider using talcum powder on their genitals amid a new legal battle in the US over whether it causes ovarian cancer.
Lauren Matthews is suing Johnson & Johnson and Australian mining giant Rio Tinto claiming she developed ovarian cancer after using the global healthcare company's talcum powder.
The case is the latest in a long line of similar legal battles launched by women who developed ovarian cancer after using Johnson & Johnson's powder and its Shower to Shower bodywash on their perineum.
Rio Tinto has been dragged into the latest fight because its former subsidiary, Luzenac America, mined the talc used as the main ingredient in Johnson & Johnson products.
Ms Matthews claims both companies were grossly negligent in failing to warn people about hazards associated with talc after several medical studies linked it to ovarian cancer, court papers filed in the Louisiana District Court show.
Australian health experts say while there is no definitive evidence of talc causing ovarian cancer, women who are concerned about its possible risks should avoid it.
Ovarian Cancer Australia recommends women stop using talcum powder on their genital area if possible.
"Ovarian Cancer Australia encourages women to do what they can to reduce their risk of developing ovarian cancer," it said.
Ovarian cancer is the most common cancer in post-menopausal women aged over 50.
Known risk factors include smoking, a family history of the disease, and endometriosis.
Scientific studies on talcum powder have had mixed results, with some reporting users have an increased risk of developing ovarian cancer while others found no risk.
The Cancer Council NSW says there is insufficient evidence to conclude talc users face a higher risk, and that it is unclear how talcum powder might influence the development of the disease.
In her court papers, Ms Matthews says she regularly dusted Johnson & Johson's talcum powder on her perineum and in 2011 was diagnosed with ovarian cancer at age 29.
She had no risk factors for the disease, genetic or otherwise.
Ms Matthews says Rio Tinto and Johnson & Johnson had a duty to know about the risks and put warnings on their powder.
Adjunct professor Terry Slevin, who chairs the Cancer Council's Occupational and Environmental Cancer Risk Committee, said warning labels don't make a lot of sense given that science doesn't clearly connect talc with ovarian cancer.
He noted that while alcohol was a known carcinogen, wine bottles aren't required to carry warnings.
"For people who are concerned and don't have to use talc, they can look to stop using it," he said.
Johnson & Johnson, which was ordered to pay $US72 million ($A94 million) and $US55 million to two ovarian cancer sufferers in separate legal cases earlier this year, said it stood by the safety of cosmetic talc.
"Multiple scientific and regulatory reviews have determined that talc is safe for use in cosmetic products and the labelling on Johnson's Baby Powder is appropriate," a spokesperson said.
