TOPLINE

Nickel and cobalt release from everyday hairdressing tools was common in Danish salons, raising the possibility of an occupational exposure risk for hairdressers. Over a third of salons contained tools that tested positive for nickel, and about a fifth contained tools that tested positive for cobalt.

METHODOLOGY

• Researchers performed a cross-sectional field study from March to June 2026 to assess the release of nickel and cobalt from hairdressing tools commonly used in Danish hair salons.
• They visited 58 participating salons and tested 266 tools: 167 scissors, 95 hair clippers, and four razors.
• Every tool was tested without cleaning, with separate spot tests for nickel and cobalt. A spot test used a cotton swab with a test liquid that changed color if the metal was released.
• The tests focused on the most worn or frequently handled metal areas. A reddish-pink color indicated a positive nickel test, and a reddish-brown color indicated a positive cobalt test.
• The primary outcome was spot-test positivity for each metal among the hairdressing tools evaluated. Secondary outcomes were positivity by tool category and whether each salon had one or more tools that tested positive.

TAKEAWAY

• Overall, 37 tools (13.9%) tested positive for nickel, and 18 (6.8%) tested positive for cobalt.
• Nickel tests were positive for 15.6% of scissors and 10.5% of hair clippers. Cobalt tests were positive for 6.6% of scissors and 6.3% of hair clippers. Of the four razors, one tested positive for nickel and one tested positive for cobalt.
• At least one tool tested positive for nickel in 22 salons (37.9%) and for cobalt in 12 salons (20.7%).

IN PRACTICE

"[Hairdressing] tools are a frequently overlooked source of metal exposure and may increase the risk of hand eczema in an already susceptible occupation. Our findings underscore the importance of proactive preventive strategies, such as careful material selection, early education during apprenticeships and stricter regulatory oversight of professional equipment," the authors wrote.

SOURCE

Kian Karimian, with the Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark, was the corresponding author of the study, which was published online on October 04, 2026, in Contact Dermatitis.

LIMITATIONS

The spot tests were semiquantitative, and negative results did not essentially rule out significant nickel release. The study could not assess the co-release of both the metals from the individual tools. Only four razors were tested, which limited the interpretation of those findings.

DISCLOSURES

The study was supported by the Danish Environmental Protection Agency under the Ministry of Environment of Denmark. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.