"Hypoallergenic" has no legal definition in the US. The same earring sold in the EU has to pass a numeric test.

I sell earrings into both markets and this is the gap between them.

EU. REACH Annex XVII entry 27. Posts inserted into pierced ears may not release more than 0.2 µg/cm² per week. Articles in direct and prolonged contact with skin — earrings, necklaces, bracelets, watch cases and straps, garment fasteners — may not exceed 0.5 µg/cm² per week. A coating has to hold that limit for at least two years of normal use. Conformity is demonstrated by CEN methods: EN 1811 for release, EN 12472 for coated articles after simulated wear.

US. No federal nickel release limit for adult jewellery. ASTM F2999, the adult jewellery standard, is voluntary. And "hypoallergenic" and "nickel free" have no regulatory definition at all — either phrase can be used without testing anything.

So the identical object is a tested product on one continent and an adjective on the other.

Worth knowing what the number is actually for: the EU limits came out of the earlier Nickel Directive, which was written around ear piercing specifically, as the sensitising exposure.

Kept by KREMAGE, the wandering portal — entry 020.