Could lipstick give you breast cancer-chemicals found in lipstick and nail varnish could trigger breast cancer.
A study has shown that butyl benzyl phthalate, or BBP, can interfere with the healthy development of breast tissue.
Environmental campaigners call for it to be banned in the cosmetic industry, where it is used to make products glossy.
The man-made substance is part of the phthalate family of chemicals, which mimic the female sex hormone oestrogen.
Phthalates are widely used to soften plastics and are found in food packaging, toys, carpets and solvents.
Past studies have linked them to birth defects, kidney problems and infertility.
They have been banned in teething rings and babies' dummies across Europe.
Now, scientists at the Fox Chase Cancer Centre in Philadelphia say that BBP - which accumulates in our fat cells - could increase the risks of breast cancer.
The team fed lactating rats with BBP, which was then absorbed by their offspring via breast milk.
The baby rats were exposed to levels of the chemical estimated to be nearly equivalent to the American Environmental Protection Agency's safe dose for humans, the researchers reported in the online journal BMC Genomics.
The chemical altered the genetic make-up of cells in the young female rat's mammary glands.
Although the effects wore off once BBP was removed from the diet, the subtle changes could have an effect later in life, the scientists say.
"We are the first to report that neonatal/prepubertal exposure to BBP induced modifications in the gene expression of the mammary tissue," said team leader Dr Jose Russo. continue to next page of toxic lipstick
Posions in Lipstick
Q. A kiss of death?
Lead in lipstick? Millions of women put on lipstick every day without ever considering whether dangerous chemicals lurk inside the tube.A study by University of California researchers found nine toxic heavy metals, including chromium, cadmium, aluminum, manganese, and lead in testing of 24 lip glosses and eight lipsticks.