Chromium(VI) in leather: where it comes from and why it is restricted
Technically reviewed: 2026-07-31
In short
Most leather is tanned with trivalent chromium, which is not hazardous in itself. Under unfavourable conditions — heat, UV, low humidity, high pH — hexavalent chromium (Cr(VI)) can form in the leather; it is a skin sensitiser and restricted in the EU. Its presence is established by laboratory measurement; for manufacturers and importers alike, measurement is what provides documented certainty.
The chemistry, briefly
Chrome tanning is the leather industry’s defining technology — the trivalent chromium (Cr(III)) it uses is stable and harmless in finished leather. The problem is oxidation: under certain conditions, part of the Cr(III) can convert to hexavalent chromium (Cr(VI)). Cr(VI) is a potent contact allergen, which is why the EU restricts it in leather articles in skin contact.
When does the risk grow?
- heat and UV exposure during production, storage or transport;
- high pH in the leather — an alkaline environment favours oxidation;
- certain fatliquors and auxiliaries that introduce oxidation-promoting components;
- long, poorly controlled storage — in containers, at high temperature.
That is how a lot that measured fine at production can measure above the limit by the time it reaches the target market.
How it is measured
Cr(VI) determination is a standard laboratory method, analysing an extract prepared from the leather. With lot-representative sampling and — near the limit — confirmatory measurement, the test yields a result fit for decisions.
What to do as a manufacturer or importer
The risk is manageable: pH control, careful auxiliary selection, storage discipline — and regular, documented measurement. For importers, a lot-level verification measurement belongs next to the supplier’s declaration: an exceedance cannot be seen or smelled — only measured.
Related standards
Where next?
A question about your own product?
Request a quote