Nickel Release Test

1、Introduction to Nickel Release

Nickel is an element that easily causes contact allergies. Nickel is absorbed through the skin after being released from nickel-containing materials and prolonged skin contact, leading to allergies in some individuals; further exposure to soluble nickel salts can result in systemic contact dermatitis (statistics show that 20% of people exhibit significant allergic reactions to nickel). Currently, for daily consumer goods such as apparel and jewelry exported to Europe, if they contain nickel-based metal accessories, testing for standard nickel release rates is generally required.

The European Union adopted Directive 94/27/EC (Nickel Release Directive) in 1994 to regulate the use of nickel (Ni) in products that have direct and prolonged contact with the skin, such as necklaces, bracelets, watch cases, watch straps, metal eyeglass frames, metal casings of consumer electronics (MP3 players, digital cameras, etc.), and metal buttons. The reason is that nickel (Ni) can cause allergic skin reactions.

According to this directive, the nickel (Ni) release rate must be less than 0.5 micrograms per square centimeter per week.

Since July 20, 2000, EU member states have prohibited the manufacture and import of products that do not comply with this directive.

On July 20, 1997, the EU issued three harmonized standards—EN1810, EN1811, and EN12472—in accordance with the requirements of 94/27/EC, specifying quantitative analysis methods for standard nickel release rates.

2. Limit Requirements for Nickel Release:

European standards specify that the nickel release rate in products such as apparel and jewelry must not exceed 0.2 μg/cm2/week. On July 20, 1997, the EU issued two new harmonized standards, EN1811 and EN12472, in accordance with the requirements of 94/27/EC, clarifying the quantitative analysis methods for standard nickel release rates.

3. Principle of Nickel Release Testing

The object to be tested for nickel (Ni) release is placed in an artificial sweat test solution for one week. Atomic absorption spectroscopy, inductively coupled plasma spectroscopy, or other suitable analytical methods are used to measure the concentration of dissolved nickel (Ni) in the solution.

4. Nickel Release Testing Methods

Total Nickel (Ni) Content Test (EN1810:2005);

Nickel (Ni) Release Test for Products with Direct and Prolonged Skin Contact (EN1811:1999, applicable to products without electroplated coatings);

Test for Nickel (Ni) Release from Coated Objects After Catalysis and Abrasion (EN12472:2005, applicable to coated products).

5. Nickel Release Test Items