Chromate Information



Other Names

Chromate ion, Chromate (VI)

Chemical Formula


CAS Number

13907 – 45 – 4

Industry Uses

Anti-corrosives; Plating; Pigments

Health Risks

Irritation; Carcinogen

What is Chromate?

Chromate is an oxoanion of chromium in the 6+ oxidation state. It is a strong oxidizing agent. In aqueous solution, chromate and dichromate are interconvertible. Chromates are used in chrome plating to protect metals from corrosion and improve paint adhesion. Chromate salts are used as pigments, and chrome yellow was a common paint for yellow school buses. Chromate containing minerals are rare. Crocoite is the most commonly found chromate mineral and occurs as long red crystals. Chromates are also used to manufacture leather products, paints, cement, and mortar. They are used extensively as corrosion inhibitors in open and closed cooling water systems.

Chromate Exposure and Health Risks

All hexavalent chromium compounds (including chromate) are toxic due to their oxidizing power. Chromates are carcinogenic, especially when airborne and cause allergic reactions. Contact with products containing chromates can lead to allergic skin reactions, dermatitis, and ulcers. The use of chromate in manufactured goods has been restricted by the EU (and by market commonality the rest of the world).


The table below summarizes the most-recent standards for Chromium concentration .




0.1 mg/L

Primary Standards – Max Contaminant Level


Sources: EPA

Measuring Chromate

Dissolved chromate concentration in water can be measured in units of parts per million (ppm). We carry kits from CHEMetrics that determine chromate levels in water from 0-10 ppm. All of our chromate products can be viewed HERE.

These Chromate kits are designed to accurately measure the chromate levels in water using the Diphenylcarbazide Method.

The K-2803 Chromate Vacu-Vials Kit is used to measure chromate levels from 0-3.5ppm.

The K-2810 Chromate Kit is used to measure chromate levels from 0-1ppm 1-10ppm.

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