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Elevated formaldehyde concentration in "Brazilian keratin type" hair-straightening products: a cross-sectional study
Mbulelo H Maneli1, Peter Smith2, Nonhlanhla P Khumalo1
1Division of Dermatology, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa.
Background:
Brazilian keratin treatment (BKT) and similar straightening products fix and retain a straight shape even when the hair is wet. Unacceptably high concentrations of formaldehyde have been reported in such products.
Objective:
We sought to measure the formaldehyde concentration in all BKT brands marketed in South Africa in 2012.
Methods:
We quantified formaldehyde by high-performance liquid chromatography with ultraviolet light detection after derivatization with dinitrophenylhydrazine. All components of 7 identified commercial brands were each tested 3 times.
Results:
The maximum safe concentration of formaldehyde set by the US Cosmetic Ingredient Review Expert Panel is less than 0.2%. Of the 7 commercial BKT brands, 6 had formaldehyde levels that ranged from 0.96% to 1.4%, ie, 5 times higher than the recommended level; these included 5 brands labeled formaldehyde-free.
Limitations:
The study is limited by not including all internationally available BKT products.
Conclusions:
Formaldehyde concentrations in BKT products may exceed recommended levels and serve as a health hazard. Industry monitoring is needed to improve compliance and protection of hairdressers and consumers.
