Which zipper components need nickel release testing?

Q: Which zipper components need nickel release testing?

Any metal component that may come into prolonged or repeated contact with the skin should be assessed for nickel release. On a zipper that means the slider, the puller, the top and bottom stops, and any rivet or snap attached to the tape. Decorative plating on these parts is also in scope if it can wear through during use.

The common European test is EN 1811, which measures nickel release in micrograms per square centimeter per week, with a limit of 0.5 for articles in prolonged skin contact. For coated items, EN 12472 simulates wear and corrosion before the release test, because a plating that passes intact can fail once the surface is abraded. Some markets apply different limits, so confirm the destination requirement.

Material choice is the cheapest control. Use a substrate that is inherently nickel-free, such as brass with a suitable barrier layer, or specify a nickel-free finish and verify it with a test report rather than a datasheet. If the zipper is used on childrenswear or on a garment worn directly against the skin, treat nickel release as a mandatory line item in the purchase specification.