Nickel and cobalt: underestimated contact allergens in hairdressers?

Abstract

Introduction: Nickel and cobalt were not regarded as pertinent contact allergens in the hairdressing business for the last decades. It was even stated that the relevance of nickel allergy in hairdressers had been overestimated for several years. Recently, the release of nickel and cobalt from a multitude of metal tools used by hairdressers in Germany was documented in two field studies. Methods: Review of two field studies. Results: In 2019, nickel release from 9.2% of 229 tested metallic hairdressing tools was evidenced, and in 2021, nickel release from 27.6% as well as cobalt release from 2.1% of 475 tested tools was detected in a total of 30 North German hairdressing salons. Tweezers, sectioning clips, hair clips, and straight razors were identified as nickel- as well as cobalt-releasing tools. Crochet hooks and tail combs were identified as only nickel-releasing tools. Discussion: A variety of metallic tools - which are used daily by hairdressers - release nickel and/or cobalt in allergologically relevant amounts. This circumstance has to be considered problematic with regard to the development of work-related allergic contact dermatitis. Thus, nickel and cobalt should possibly receive greater attention as potential contact allergens in the hairdressing business. Conclusion: The proven nickel and cobalt release from metallic hairdressing tools might entail legal ramifications in terms of insurance law. In case of nickel and cobalt allergies within the occupational group of hairdressers, metal tools might be considered as potential sources for nickel and cobalt exposure.