Formaldehyde concentrations in Brazilian keratin hair straightening products may be high enough to serve as a health hazard, a recent study reports.
Researchers in South Africa measured formaldehyde concentrations in seven commercial Brazilian keratin treatments marketed in South Africa in 2012 using a high-performance liquid chromatography with ultraviolet light detection after derivatization with dinitrophenylhydrazine.
While the maximum safe concentration set by the U.S. Cosmetic Ingredient Review Expert Panel is less than 0.2 percent, the researchers found that six of the brands studied, five of which were labeled “formaldehyde free”, actually had levels ranging five times higher than this recommended level (0.96 to 1.4 percent).
The authors tested each brand three times.
“Industry monitoring is needed to improve compliance and protection of hairdressers and consumers,” the authors concluded.