RESUMEN
BACKGROUND: The high risk of occupational skin disease among hairdressers, caused by skin exposure to irritants and sensitizers, such as hair dye substances, is of great concern. OBJECTIVES: The aim of the present study was to assess how the various tasks involved in hair dyeing contribute to hairdressers' exposure to hair dye, in order to enable the formulation of well-founded recommendations on working routines that will reduce exposure and prevent occupational disease. METHODS: Skin exposure to hair dye was measured for 20 hairdressers applying highlights and all-over hair colour with the hand rinsing technique. Resorcinol was used as a proxy for hair dye exposure. RESULTS: Applying hair dye and cutting the newly dyed hair were the tasks that contributed most to exposure in treatments for highlights. After cutting all-over-coloured hair, all hairdressers had measurable amounts of hair dyes on both hands. CONCLUSIONS: Hairdressers are exposed to hair dye ingredients during all steps of the hair dyeing procedure. Cutting newly dyed hair contributes significantly to exposure. For the prevention of occupational disease resulting from hair dye exposure, we suggest cutting hair before dyeing it, and wearing gloves during all other work tasks.