title: Elevated formaldehyde concentration in "Brazilian keratin type" hair-straightening products: a cross-sectional study.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors: Division of Dermatology, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa.
authors: Mbulelo H
authors: MH
authors: Maneli
authors: Division of Pharmacology, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa.
authors: Peter
authors: P
authors: Smith
authors: Division of Dermatology, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa. Electronic address: n.khumalo@uct.ac.za.
authors: Nonhlanhla P
authors: NP
authors: Khumalo
mesh_terms: D001461:Barbering; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003257:Consumer Product Safety; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring; D005557:Formaldehyde / Q000032:analysis*; D006203:Hair Preparations / Q000737:chemistry*; D006801:Humans; D053564:Keratins, Hair-Specific; D009682:Magnetic Resonance Spectroscopy; D040541:Marketing; D008452:Maximum Allowable Concentration; D016273:Occupational Exposure / Q000032:analysis*; D018570:Risk Assessment; D013019:South Africa
chemical_list: D006203:Hair Preparations; D053564:Keratins, Hair-Specific; D005557:Formaldehyde
keywords: BKT; Brazilian keratin treatment; Brazilian keratin treatments; DNPH; DNPHF; HPLC; dinitrophenylhydrazine; formaldehyde; formaldehyde dinitrophenylhydrazone; hair; hairdressing; high-performance liquid chromatography; public health