For most people, not seriously. Copper and brass react with sweat and leave a green mark, which washes off and isn't harmful. Copper allergy is uncommon. The bigger issue with brass jewelry on skin is what's usually added to it: a nickel layer under a plated finish, and sometimes lead in the alloy itself. For earrings in a child's ear, worn for days at a time, those additions matter more than the copper does. Our materials page sets out what we use instead.
What each metal is
Copper is a pure metal, reddish-orange, soft and easy to shape. It tarnishes to brown and eventually green.
Brass is an alloy of copper and zinc, commonly around two-thirds copper. It's yellow, cheap, easy to cast and polish, and it's one of the most common base metals in fashion jewelry.
Bronze is an alloy of copper and tin. It's darker and harder than brass, and it behaves much the same against skin.
All three are copper-based, and copper is what does the reacting.
Why they turn skin green
Sweat contains salt and acids. When it sits against copper, the surface reacts and forms copper salts, which are green. They transfer to the skin as a stain.
It isn't an allergy. The mark is a chemical stain, not an immune reaction, and it washes off with soap and water.
It's worse in some conditions. Humid weather, sport, lotion, sunscreen and a lot of sweat all speed it up. Skin chemistry varies too, so the same piece can mark one child and not another.
On an earring, it's also a signal. A green ring on a lobe from a piece sold as gold or silver tells you the finish has worn through to a copper-based metal underneath.
Brass, copper and steel compared
| Copper | Brass | Bronze | S316L Surgical Steel | |
|---|---|---|---|---|
| What it is | Pure metal | Copper and zinc | Copper and tin | Iron, chromium, nickel, molybdenum |
| Green marks on skin | Common | Common | Common | No |
| Nickel in the metal | No | Not usually | Not usually | Roughly 10 to 14%, held in the alloy |
| Nickel added in plating | Sometimes | Often | Sometimes | Not in our range |
| Lead in the alloy | No | Sometimes, in leaded brass | Sometimes | No |
| Tarnishes | Yes | Yes | Yes | No |
| Typical jewelry use | Bracelets, rings, craft pieces | Plated fashion jewelry | Rings, pendants | Earrings and body jewelry |
Where brass becomes the problem
The nickel layer. Plated brass jewelry very often has a layer of nickel applied first, so the gold or silver colored finish adheres and looks smooth. When the top finish wears, that nickel is what touches her skin. Nickel allergy affects around one in five people in North America, and in the United States there's no legal limit on how much nickel an earring may release.
Leaded brass. Some brass has lead added to make it easier to machine. Children's products sold in the United States must meet a strict lead limit, but jewelry sold for adults doesn't have to.
Wear in the places you can't see. The post inside the piercing and the butterfly back take the most friction, so they wear through first, long before the front looks tired.
Corrosion in a piercing. A pierced ear holds an earring in warm, damp skin for days. That's the environment in which copper alloys corrode fastest.
Is uncoated copper jewelry any better?
It avoids the nickel layer, which is a real advantage. It still stains, it still tarnishes, and it's soft, so a copper post bends easily. Copper allergy exists but is uncommon, so most people wear copper without any reaction beyond the green mark. For a bracelet that's a minor inconvenience. For a post that lives inside a child's earlobe, it's not a material we'd choose.
How to tell whether an earring is brass underneath
- Look at the post and the back. A yellow or pinkish metal showing through a silver or gold finish is usually brass or copper.
- Watch her skin. A green mark after a few days points to a copper-based metal.
- Read the listing. "Gold tone", "fashion jewelry" and no named base metal usually means brass.
- Swab for nickel. A dimethylglyoxime spot test turns pink if nickel is coming off the surface. Test the post and the back.
What we do
The way most fashion jewelry is made comes down to two forces, cost and speed. Brass is cheap, fast to cast and takes a plated finish easily, which is exactly why it sits under so many earrings that are sold as something else. When I was sourcing, the answer to "what's the base metal?" was usually the answer that closed the sale, not the full one.
We don't use brass, copper or bronze anywhere in an earring, and we don't plate nickel onto anything.
S316L Surgical Steel, used on its own throughout the Polished Surgical Steel range, front, post and butterfly back, with nothing plated over it. It contains nickel, as stainless steels do, and its corrosion resistance is what keeps that nickel in the metal.
24K Pure Gold, which is pure 24 karat gold applied onto a S316L Surgical Steel core with Aunix™ 24K, our engineered gold finish. It's a gold-plating process, and we say so, and the core under it is steel rather than brass.
Independently tested by SGS to ASTM F2923, CPSIA and BSEN 71-3, with nickel release not detected under EN 1811 and lead below a tenth of the United States legal limit. Report BTO 341803/1, and you can ask me for it.
The plainest way to rule out a copper-based metal is a pair with nothing plated over anything, which is what the 5mm Star Stud Earrings in S316L Surgical Steel are. The full range is on the Polished Surgical Steel collection.
Questions parents ask next
Is the green mark from copper jewelry harmful? No. It's a stain from copper salts, and it washes off with soap and water. On an earring, it's more useful as a sign of what the metal is.
Can you be allergic to brass earrings? A reaction to brass earrings is more often a reaction to nickel in the plating than to the brass. Copper allergy exists, but it's uncommon.
Can she wear brass jewelry in the shower? Water and soap speed up tarnish on brass, and shampoo residue collects behind the back. Take brass pieces off before bathing.
How do I stop brass jewelry turning her skin green? Keep it dry, keep lotion and sunscreen off it, and clean it often. Clear nail polish on the inside wears away quickly and isn't something to put on an earring post.
Is brass jewelry safe for kids? Brass sold as children's jewelry in the United States must meet the children's lead limit. Nickel in the plating isn't limited, so ask for a nickel release result.
Related reading
- Why do earrings turn ears green?
- What does it mean when earrings turn your ears green?
- What is nickel plated silver?
- How do I stop earrings from turning her ears green?
About the author. Matt Westmore is the founder of purepixxi. He came to children's jewelry from manufacturing and sourcing rather than marketing, which means he has walked the factory floors and knows what is actually inside a product rather than what a label says about it. purepixxi uses two materials only, names them exactly, and has them independently tested.
