Leucomalachite Green Reference Standards

HPC supplies leucomalachite green (CAS 129-73-7) and D5- or D6-labelled analogues. In the EU, 0.5 µg/kg is a reference point for action for the sum with malachite green, not an MRL or permitted residue.

Product	Catalog No./ CAS No.	Quantity	Price
ISO 17034 Reference Material D5-Leucomalachite green	676847 947601-82-3	1X10MG	Please log in.
ISO 17034 Reference Material D6-Leucomalachite green	692727 1173021-13-0	1X10MG	Please log in.
ISO 17034 Certified Reference Material D6-Leucomalachite green solution Concentration: 100 µg/ml Solvent: Acetonitrile	692728 1173021-13-0	1X1ML	Please log in.
ISO 17034 Reference Material Leucomalachite green	674880 129-73-7	1X100MG	Please log in.
ISO 17034 Certified Reference Material Leucomalachite green solution Concentration: 100 µg/ml Solvent: Acetonitrile	693435 129-73-7	1X5ML	Please log in.

Identity and analytical relevance

Leucomalachite green is the reduced, colourless metabolite of malachite green. It is analytically relevant in residue control because malachite green can be converted to and persist as the leuco form in exposed fish tissue.

CAS Registry Number: 129-73-7
Molecular formula: C₂₃H₂₆N₂
Molecular weight: 330.5 g/mol

EU reference point for action

The consolidated version of Commission Regulation (EU) 2019/1871 applicable from 3 December 2024 sets a reference point for action of 0.5 µg/kg for the sum of malachite green and leucomalachite green in food of animal origin. A reference point for action is used for control action concerning non-allowed pharmacologically active substances. It is not an MRL and must not be described as a permitted residue concentration.

Carcinogenic-hazard classification

In IARC Monographs Volume 129, published in 2022, leucomalachite green was classified as Group 2B, possibly carcinogenic to humans. IARC stated that the classification was based on sufficient evidence of carcinogenicity in experimental animals, while the mechanistic evidence was limited and the evidence in humans was inadequate. This is a hazard classification; it does not quantify risk at a particular exposure level.

Available HPC reference materials

The current range includes leucomalachite green as neat material (item 674880, 100 mg) and as a 100 µg/mL solution in acetonitrile (item 693435, 5 mL). Isotope-labelled options include D5-leucomalachite green (item 676847, 10 mg), D6-leucomalachite green (item 692727, 10 mg) and a 100 µg/mL D6 solution in acetonitrile (item 692728, 1 mL).

Primary sources and review status

Regulatory and hazard information reviewed on 16 July 2026. Confirm the current control rule, matrix and jurisdiction before interpreting a result.