Experimental evaluation of nickel and cobalt release from tools and self-reported prevalence of nickel and cobalt allergy in the German hairdressing trade

Abstract

Background Nickel release from some metal tools in the hairdressing trade has been sporadically evidenced, whereas data about cobalt release from metal tools in the hairdressing trade are lacking. Objectives To screen metal tools for nickel and cobalt release and to estimate the prevalence of nickel allergy and cobalt allergy in the German hairdressing trade. Methods Four hundred seventy-five metal tools in the hairdressing trade were tested in three North German states with a nickel spot test for nickel release and with a cobalt spot test for cobalt release. Seventy hairdressers were surveyed with a standardized questionnaire to collect data about the tested metal tools as well as the prevalence of nickel allergy and cobalt allergy. Results One hundred thirty-one of 475 metal tools (27.6%) - 60 of 60 hair clips (100%), five of five crochet hooks (100%), 24 of 40 tweezers (60.0%), 33 of 75 sectioning clips (44.0%), five of 32 straight razors (15.6%), and four of 45 tail combs (8.9%) - released nickel and 10 of 475 metal tools (2.1%) - three of 40 tweezers (7.5%), four of 60 hair clips (6.7%), one of 32 straight razors (3.1%), and two of 75 sectioning clips (2.7%) - released cobalt. Eight of 63 female hairdressers (12.7%) suffered from nickel allergy and two of 63 female hairdressers (3.2%) suffered from cobalt allergy. Conclusions Metal tools in the German hairdressing trade - with which a prolonged skin contact is intended - release nickel and cobalt in allergologically relevant amounts and thus should be taken into account as occupational sources of exposure to nickel and cobalt.