Nickel allergy for a person develops when he or she is exposed to this metal. Once the exposition exceeds a threshold value, which is different for each person, a hypersensitivity appears, which can later translate in an allergic contact dermatitis. The increase in the number of people allergic to Nickel since the second half of the 19th century has lead to an awareness of this public health issue.
Limiting the exposition to Nickel allows limiting the hypersensitivity, which is why norms have been set up in the 90s (European directive 94/27/CE) to regulate the Nickel content released by commodities destined to be in prolonged contact with the skin, like jewelry, zips, buttons… This norm has been set to an exposition limit of 0,5 micrograms of Nickel per cm² of skin per week. An object must not exceed this Nickel release limit to be in accordance with the European norm.
However, the hypersensitivity and contact dermatitis induced by Nickel are still widely spread. Different factors can explain this:
First of all, the exposition limit of 0,5 micrograms / cm² / week was kept as the threshold to avoid new hypersensitivities. For the persons already sensitized to this metal, this exposition can be sufficient to trigger reactions of an allergic type.
Then there is the cumulative dose. Nickel is not forbidden as such, but it is only its content in an object that cannot exceed this threshold value (more accurately, the Nickel released by an object cannot reach this threshold value). By multiplying the sources of exposition, this threshold value can be exceeded in total, even if all of the concerned objects respect the legislation.
The legislation concerns consumer goods, but many other concerned objects are excluded from it. To give only one example: coins like those of 2 euros contain Nickel.
This diversity of exposition sources explains why Nickel is one of the substances registered in France and other countries in the register of causes that can lead to a declaration of occupational disease.
Other metals, also targeted by the Protective Cream HPS, like Chromium, are also responsible for allergic contact dermatitis, in general public as in the workplace (construction), without the regulation being as advanced as for Nickel. The Protective Cream HPS protects the skin from Nickel, Chromium, and other irritant metals, by stopping them from penetrating the skin.
These applications and the prevalence of these contact dermatitis induced by metals have already given cause for recommendations from occupational physicians to use the Protective Cream HPS.
Finally, despite the presence of a well-defined regulation, there are some objects, in particular, imported objects, which do not respect the release Nickel content defined by the European Union.