Since some people are allergic to nickel, the EU nickel directive regulates how much nickel may be released onto the skin per week. For earrings, these are a maximum of 0.2 micrograms per square centimeter per week (i.e. 0.2 millionth of a gram). All our piercing studs and earrings fall well below this allowable value and are thus nickel-safe and allergy free. In fact, our piercing studs are hypoallergenic, nickel-safe, lead-, cadmium- and cobalt-free!