Nickel

Nickel is the most frequent cause of contact allergy, affecting up to 22% of women and 6% of men, and hand eczema is reported by 30–40% of nickel-allergic individuals. Certain occupational groups are much more affected. Occupational nickel skin exposure is an important risk factor for hand eczema. Exposure reduction is essential for prevention. Pure nickel metal, nickel-containing alloys, coatings, and compounds have different ability to release nickel ions and to cause nickel allergy and allergic nickel dermatitis. The dimethylglyoxime test is useful in the assessment of nickel exposure and exposure reduction in the workplace and elsewhere. Skin exposure to nickel can be quantified, and knowledge on exposure levels can contribute to improved risk assessment and prevention. Nickel release from articles intended for prolonged contact with the skin is restricted in the EU. In an attempt to improve protection, the European Chemical Agency (ECHA) has defined that “prolonged contact” in relation to nickel is 10 min or more and has explained that the restriction covers articles for workers, professionals, and consumers. It should be recalled that also short and repetitive contact contributes significantly to nickel exposure.