Nail Polish Chemical Under Scrutiny

Researchers at Duke University, Boston University, and the advocacy organization Environmental Working Group have found a link between the use of nail polish and exposure to triphenyl phosphate (TPHP), a suspected endocrine disruptor (Environ. Int. 2016, DOI: 10.1016/j.envint.2015.10.005). TPHP is added to some nail polishes to make them flexible. It is a common replacement for the plasticizer dibutyl phthalate, which has been associated with adverse reproductive effects. The scientists found that levels of diphenyl phosphate, a metabolite of TPHP, increased sharply in the urine of women 10 to 14 hours after they painted their nails with polish containing TPHP. The chemical is also used to manufacture plastics and as a fire retardant in foam furniture. Recent research suggests that TPHP interacts with a protein that is involved in regulating metabolism and the production of fat cells. It is unclear, however, whether the chemical contributes to weight gain and obesity. The study prompted one U.S. lawmaker to call for legislation to overhaul how cosmetics are regulated. Consumers “deserve to know that they are making safe choices,” says Rep. Frank Pallone Jr. (D-N.J.).