Gold-plated jewelry is created by applying a thin layer of gold onto a base metal using electroplating. A primary concern for many consumers is the presence of nickel, which can cause allergic contact dermatitis, commonly known as a nickel allergy. This sensitivity is widespread, affecting an estimated 8.6% of the general population worldwide, particularly among those exposed through piercings and jewelry. Since the outer gold layer is extremely thin, the core question is whether the underlying materials contain this common allergen. The answer depends entirely on the manufacturing process and the base metals chosen.
The Purpose of Nickel in Jewelry
Manufacturers frequently incorporate nickel into jewelry because it offers several functional benefits. Nickel provides hardness and durability, preventing the relatively soft outer gold layer from quickly wearing away. It also acts as an excellent binding agent, promoting strong adhesion between the base metal and the gold layer applied during electroplating. Furthermore, nickel offers substantial corrosion resistance, shielding the underlying base metal from moisture and oxidation. This reliance on nickel creates a risk, however, as the plating will eventually wear down, exposing the nickel and potentially triggering an allergic reaction.
The Layered Structure of Plated Jewelry
Gold-plated jewelry is constructed with multiple metallic layers, starting with an innermost base metal, typically an inexpensive alloy like brass or copper. Directly over this base metal, jewelers often apply an intermediate layer, sometimes called a barrier or underplate. Nickel is traditionally used for this barrier because it prevents base metal atoms from migrating through the gold and causing surface tarnish. This diffusion barrier is crucial for maintaining the gold’s appearance. The final, outermost coat is an extremely thin layer of gold, and nickel-free plating must substitute the barrier layer with alternative metals like palladium or rhodium.
How to Ensure a Product is Nickel-Free
Consumers with nickel sensitivity must seek specific assurances regarding the metal composition of the underlying layers. Look for clear labeling that explicitly states the product is “nickel-free” or “nickel-safe,” as the term “hypoallergenic” does not guarantee the absence of nickel. Consumers should verify the material composition or look for third-party certifications, as these terms often lack a universal regulatory standard. Compliance with the European Union’s Nickel Directive is a reliable indication of a safer product, as it sets a maximum nickel release rate for items in prolonged contact with skin. Naturally nickel-free materials include titanium, high-carat solid gold (14k or higher), or gold vermeil; a simple at-home nickel test kit can also confirm the presence of the metal in existing jewelry.