Women who use baby powder with talc have a 30 percent increased risk of developing ovarian cancer, according to the American Cancer Society.

While lab studies exposing rats, mice, and hamsters to asbestos-free talc have resulted in mixed outcomes – some showing tumor formation, others not finding anything – some human studies report an elevated risk of baby powder danger related to ovarian cancer.

The theory is that talcum powder particles can migrate from the vagina to the ovaries after being applied to the genital area on sanitary napkins, diaphragms or condoms. To reach the ovaries, the particles would travel through the uterus and fallopian tubes.

“One analysis combining data from 16 studies published before 2003 found about a 30 percent increase in ovarian risk among talc users,” the American Cancer Society reports. “The average woman’s lifetime risk of ovarian cancer is about 1.4 percent, so even with a 30 percent increase, her lifetime risk would be about 1.8 percent. Still, talc is widely used in many products, so it is important to determine if the increased risk is real. Research in this area continues.”

Another study has suggested genital talcum powder use may slightly increase the risk of endometrial (uterine) cancer in post-menopausal women.

In 2013, a federal jury in South Dakota found in a Johnson’s baby powder cancer lawsuit that Johnson & Johnson powders containing talc contributed to Deane Berg getting ovarian cancer in 2006.

Berg sued Johnson & Johnson, Luzenac America and its parent company, Rio Tinto Materials, alleging negligence and failure to warn consumers about the risk of ovarian cancer from talcum powder dusting.

Berg alleges in the Johnson’s baby powder cancer lawsuit that every day for 30 years, Berg used Johnson & Johnson’s talc-based products, including Shower to Shower, as part of her hygiene routine. The products contributed to her contracting the deadly disease, the jury found after hearing the results of three different doctors who examined cancerous tissues extracted from Berg, concluding that talc particles caused the ovarian cancer.

Tens of thousands of other women allege in baby powder cancer lawsuits that they too got the disease as a result of regularly applying baby powder, or talcum-based powder, in the genital area.

According to the American Cancer Society, talcum-based powders – comprised of magnesium, silicon and oxygen – are good at absorbing moisture and mitigating friction, which in turn helps keep the skin dry and rash-free. Talc is present in many cosmetic products, perhaps most notably in baby powder and adult body and facial powders, such as Johnson’s Baby Powder and Shower to Shower.

The American Cancer Society suggests that anyone concerned about the link between ovarian cancer and talc “may want to avoid or limit their use of consumer products that contain it. For example, they may want to consider using cornstarch-based cosmetic products instead. There is no evidence at this time linking cornstarch powders with any form of cancer.”

Harvard epidemiologist Daniel Cramer estimates that using talcum powder in perineal hygiene leads to 45 percent – or some 10,000 – ovarian cancer diagnoses each year. For 2013, the ACS estimated 22,240 women would be diagnosed with the disease and 14,030 of them would die of ovarian cancer that same year.