A sweat test soaks or exposes jewellery to artificial sweat, a lab solution made to match human perspiration, then checks for colour change, corrosion or metal released. It shows how a piece will react on skin far better than a salt spray test does.
There are two different reasons to run one: to check how the finish holds up, and to check how much nickel the piece releases, which is regulated in the EU and UK.
Sweat tests for finish and colour
Here the piece is exposed to artificial sweat for a set time, often with warmth, and then compared with an untested piece. Labs look for darkening, spots, green corrosion and loss of shine. The test is useful for rose gold and copper-rich finishes, and for pieces such as rings and bangles that sit against skin.
As with salt spray, set the method, duration and pass rule in advance, and test your approved sample first so you have a benchmark.
Nickel release testing
EN 1811 is the reference method for measuring nickel release from items in direct and prolonged skin contact. The item is placed in artificial sweat for a set time and the nickel released is measured. Under EU REACH, the limit is 0.5 micrograms per square centimetre per week for such items, and 0.2 for posts inserted into pierced ears or other piercings. The UK applies the same limits.
For plated items, EN 12472 is used first to simulate wear and corrosion, so the test reflects what happens once the top layer starts to wear. That matters because a nickel underlayer may pass when new and fail after wear.
When to run sweat tests
- Before you approve a new supplier or finish.
- Whenever you sell in the EU or UK, for nickel release on each design family with skin contact.
- When customers report discolouration or skin marks.
- On repeat orders at agreed intervals, to confirm the process has not changed.
Practical tips
- Ask the lab which parts of the piece will be tested, since posts, backs and clasps often differ from the front.
- Keep the test report with the design code, so you can match it to future lots.
- Ask the maker to confirm that materials and plating stay the same between the tested sample and bulk.
What this means for a buyer
If you sell in Europe, a nickel release test is not optional, and a finish sweat test is a cheap way to avoid returns. See which certifications and reports to ask for.
Creston & Co works for buyers only, for a fixed fee agreed in writing. We draw samples in Rajkot, send them to NABL-accredited labs and keep reports matched to each design. Start with a free sourcing review.