title: Chlorhexidine in cosmetic products - a market survey.
abstract: BACKGROUND
  Chlorhexidine may cause type I and type IV allergy. Some chlorhexidine-allergic individuals have been exposed in the healthcare setting as patients or healthcare workers, but for others the source of sensitization is unknown. Chlorhexidine may be used as a preservative or an antimicrobial agent in cosmetic products at a concentration up to 0.3%, as set by the European Cosmetics Directive (now Regulations).
  
  
  OBJECTIVE
  To identify cosmetic product types containing chlorhexidine, and to measure the concentration of chlorhexidine in selected products.
  
  
  METHODS
  Between February 2013 and April 2013, we checked for chlorhexidine in cosmetic products in 14 supermarkets, one hairdressing salon and one beauty and retail store in Copenhagen, Denmark by reading the ingredient labels. The chlorhexidine concentration was measured in 10 selected products by high-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector.
  
  
  RESULTS
  Chlorhexidine was found in 80 of 2251 checked products (3.6%) in the following categories: hair products (57/760), creams (9/324), face washes (4/24), wet wipes (4/63), skin tonics (3/22), make-up removers (2/25), and mouth washes (1/17). Chlorhexidine concentrations were 0.01-0.15%.
  
  
  CONCLUSIONS
  We found chlorhexidine in various cosmetic product types, predominantly aimed at females, and in hair products. The measured chlorhexidine concentrations were all within the permitted limit. The relevance for allergic sensitization should be further explored.
authors.affiliation: Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, Ledreborg Allé 40, 1, DK-2820 Gentofte, Denmark; Department of Dermato-Allergology, Allergy Clinic, Copenhagen University Hospital Gentofte, Niels Andersens Vej 65, DK-2900 Hellerup, Denmark.
authors.forename: Morten S
authors.initials: MS
authors.lastname: Opstrup
authors.forename: Jeanne D
authors.initials: JD
authors.lastname: Johansen
authors.forename: Rossana
authors.initials: R
authors.lastname: Bossi
authors.forename: Michael D
authors.initials: MD
authors.lastname: Lundov
authors.forename: Lene H
authors.initials: LH
authors.lastname: Garvey
mesh_terms: D002710:Chlorhexidine / Q000009:adverse effects / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D003358:Cosmetics / Q000737:chemistry*; D003718:Denmark; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000139:chemically induced; D006969:Hypersensitivity, Immediate / Q000139:chemically induced; D008297:Male
chemical_list: D003358:Cosmetics; D002710:Chlorhexidine
keywords: allergy; chlorhexidine; cosmetic products; exposure concentration; market survey