Sodium dichromate

Sodium dichromate (CAS 10588-01-9), also known as sodium bichromate or disodium dichromate, is an inorganic chromium(VI) salt supplied as a dihydrate or anhydrous form. It is a strong oxidising agent used across industrial processing applications where controlled oxidation or metal surface treatment is required.

In leather tanning, sodium dichromate acts as an oxidising precursor in chrome tanning baths, converting trivalent chromium compounds to reactive species that cross-link collagen fibres. In metal surface treatment and corrosion inhibition, it forms a protective chromate conversion layer on aluminium, zinc, and magnesium substrates by reacting with the base metal surface.

Sodium dichromate is subject to REACH authorisation requirements under Annex XIV due to its classification as a substance of very high concern (SVHC). Procurement must confirm current authorisation status and end-use conditions before supply. It is available in technical and industrial grades, typically in 25 kg bags or bulk quantities.