Zinc chromate

Zinc chromate (CAS 13530-65-9, EC 236-878-9) is an inorganic zinc salt of chromic acid, commercially known under designations including CI 77955, Pigment Yellow 36, and Zincro ZTO. It falls within the salts and minerals category and carries the molecular formula CrH2O4.Zn.

In anticorrosion primer coatings for aerospace structures and automotive bodywork, zinc chromate functions by releasing chromate ions that passivate metal surfaces, forming a protective oxide layer that interrupts electrochemical corrosion reactions. It is also used as a pigment in industrial printing inks and construction coatings where colour stability under UV exposure is required.

Zinc chromate is subject to REACH regulation as a substance of very high concern due to its hexavalent chromium content, and procurement must account for authorisation requirements under Annex XIV. Suppliers typically offer it as a dry crystalline powder in technical grade. Buyers should confirm SDS documentation and regional restriction compliance before sourcing.