1 Department of Environmental Science - Environmental chemistry & toxicology, Department of Environmental Science, Science and Technology, Aarhus University2 Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, DK-2820 Gentofte, Denmark3 National Allergy Research Centre, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte4 Department of Environmental Science - Atmospheric chemistry and physics (Atmospheric proceses) (ATPRO), Department of Environmental Science, Science and Technology, Aarhus University5 National Allergy Research Centre, Gentofte Hospital, University of Denmark6 Department of Dermato-Allergology, Allergy Clinic, Copenhagen University Hospital Gentofte, DK-2900 Hellerup, Denmar7 Department of Environmental Science - Atmospheric chemistry and physics (Atmospheric proceses) (ATPRO), Department of Environmental Science, Science and Technology, Aarhus University
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). OBJECTIVES: 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.