At United, we make sure that most of the alloys are made to be in compliance with the Nickel Release Test. Each Nickel based white alloy is alloyed with pure gold for 10 karat, 14 karat and 18 karat and made into a sample sheet. This sheet is polished to a mirror shine and shipped to Birmingham Assay Lab in London, UK or their subsidiary office at New York for nickel release testing.

Copies of the original Nickel Release tests are available from United for a majority of the white gold alloys for different karats.

The Nickel release test is done in a lab in compliance to EN1811:1998 regulation. A sample piece of a known surface area, is placed in an artificial perspiration solution for a week. This solution is then tested for the amount of nickel leached into it. The amount of nickel present is reported as Nickel released in micrograms per inch per week. The regulation says if the amount of nickel in the solution is less than 0.5 micrograms per inch per week then the jewellery or material is in compliance to EN 1811:1998 and can be marketed in Europe.

The European Direction BSEN: 12472 says that -- No person shall supply any product intended to come into direct and prolonged contact with the skin which -
(a)contains nickel or a nickel compound; and
(b)has a non-nickel coating *,
* unless the non-nickel coating is sufficient to ensure that the rate of nickel release from the parts of the product coming into direct and prolonged contact with the skin will not exceed 0.5 micrograms per square centimeter per week for a period of at least two years of normal use of the product.

BSEN 12474 says that -- For nickel based jewellery articles that are pierced through the skin such as earring posts. Nickel content in the alloy should not exceed 0.05 %. There is NO NICKEL RELEASE TEST required.

Experiments have shown that the amount of nickel leached out from a piece of jewellery depends on the shape, size, karat and finish of the jewellery. Even though a particular white gold alloy, by United, with a particular karat has passed the nickel release test, it does not guarantee that all jewellery made with this alloy for that respective karat will automatically pass the nickel release test. It is the responsibility of the customer or jewellery manufacturer to have a jewellery piece tested for obtaining permission prior to marketing this jewellery in Europe.