This test paper allows the quick and easy detection of chromate (CrO_⁴^₃-). Cr(III) ions must be converted to Chromate prior to the detection.

• Colour change: White to violet

For non-destructive testing of materials apply a drop of acid solution (1 part hydrochloric acid 37% + four parts hydrogen peroxide 3%) to the degreased surface. After 10 to 30 seconds add a drop sodium hydroxide (NaOH).

Limit of sensitivity: 2 mg/l Cr3+ or 5 mg/l CrO42–