OAKLAND (KPIX 5) -- A joint study by Duke University and the Environmental Working Group, found what comes out of the nail polish bottle ends up not just on your nails, but inside your body.
Researchers found a metabolite of the common nail polish chemical Triphenyl Phosphate, or TPHP, in the bodies of every woman who volunteered to paint her nails for the study.
TPHP is widely used in nail polish for durability and flexibility. It is also used as a flame retardant and plastics manufacturing.
"This chemical had increased by 7-fold in the urine at about 10-14 hours after they painted their nails," said Tasha Stoiber of the Environmental Working Group.
EWG believes the chemical is absorbed though the capillaries in the cuticle and that other solvents in the polish may actually make the nails themselves more permeable.
EWG acknowledged that more research is need on the effects of TPHP in humans, but the group said animals studies indicate TPHP is an endocrine disruptor which is especially concerning for little girls.
"Endocrine disruptors interfere with the natural hormone signaling in your body. Girls and teenagers in their critical stages of development should avoid these types of chemicals," said Stoiber.
EWG also pointed to new research that may link TPHP to weight gain and obesity.
The Personal Care Products Council, the industry group representing the nail polish manufacturers, released a statement that called the research "speculative, misleading" and said it "does not use sound science to assess the safety of an ingredient which has a long and well documented history of safe use."
The council's statement also pointed out that "(TPHP) has been widely and safely used across many industries," including to prevent "electrical, automobile and furniture fires."
EWG found TPHP listed as an ingredient in about 1,500 nail products. However, researchers said they also found polishes that also contained the ingredient but did not list it on the label.
In defense of the widespread use of the ingredient, The Personal Care Council said it doesn't believe that nail polish is an important contributor to long-term TPHP exposure.
EWG disagreed stating that the average woman paints her nails once a week.
"The good news is that consumers do have options," said Stoiber.
EWG has compiled a list of brands that don't use TPHP as an ingredient.
According to EWG's Skin Deep® cosmetics database, about 50% of the 3000 nail polishes listed don't contain TPHP.
The group launched a consumer petition to pressure popular nail polish brands including Sally Hansen, OPI and Wet N Wild, to stop using TPHP as an ingredient.
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