Skin Toxicity of Selected Hair Cosmetic Ingredients: A Review Focusing on Hairdressers

Int J Environ Res Public Health. 2022 Jun 21;19(13):7588. doi: 10.3390/ijerph19137588.


The safety assessment of cosmetics considers the exposure of a 'common consumer', not the occupational exposure of hairdressers. This review aims to compile and appraise evidence regarding the skin toxicity of cysteamine hydrochloride (cysteamine HCl; CAS no. 156-57-0), polyvinylpyrrolidone (PVP; CAS no. 9003-39-8), PVP copolymers (CAS no. 28211-18-9), sodium laureth sulfate (SLES; CAS no. 9004-82-4), cocamide diethanolamine (cocamide DEA; CAS no. 68603-42-9), and cocamidopropyl betaine (CAPB; CAS no. 61789-40-0). A total of 298 articles were identified, of which 70 were included. Meta-analysis revealed that hairdressers have a 1.7-fold increased risk of developing a contact allergy to CAPB compared to controls who are not hairdressers. Hairdressers might have a higher risk of acquiring quantum sensitization against cysteamine HCl compared to a consumer because of their job responsibilities. Regarding cocamide DEA, the irritant potential of this surfactant should not be overlooked. Original articles for PVP, PVP copolymers, and SLES are lacking. This systematic review indicates that the current standards do not effectively address the occupational risks associated with hairdressers' usage of hair cosmetics. The considerable irritant and/or allergenic potential of substances used in hair cosmetics should prompt a reassessment of current risk assessment practices.

Keywords: cocamide diethanolamine; cocamidopropyl betaine; cosmetics; cysteamine hydrochloride; hairdresser; hairdressing; hand eczema; polyvinylpyrrolidone; polyvinylpyrrolidone copolymers; sodium laureth sulfate.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / adverse effects
  • Cysteamine
  • Dermatitis, Allergic Contact* / etiology
  • Hair Preparations* / toxicity
  • Humans
  • Irritants
  • Occupational Exposure* / adverse effects
  • Occupational Exposure* / analysis


  • Allergens
  • Hair Preparations
  • Irritants
  • Cysteamine

Grants and funding

This systematic review is supported by a grant from Uni Europa–The European Global Services Union (Project VS/2019/0440: “Promoting the autonomous implementation of the European framework agreement on occupational health and safety in the hairdressing sector”). Other than being given the opportunity to provide input to the initial Delphi process to identify relevant substances, the sponsor had no role in the development or in the performance of the systematic review and the publication of its results.