COT statement on surveillance for malachite green and leucomalachite green in farmed fish

The COT was asked by the Veterinary Medicines Directorate to consider the results of surveillance for residues of malachite green (MG), a compound used for the treatment of infections in farmed fish, found in retail trout purchased in the United Kingdom during the years 1996-1998.

The Committee noted that the predominant residue in farmed fish is leucomalachite green (LMG), rather than the parent compound, and that previously it has not been possible to analyse for this compound. It sought the opinion of its sister committee, the Committee on Mutagenicity (COM) on new toxicity data. COM indicated that it would be prudent to assume that MG and LMG are potential in vivo mutagens. The Committee expressed concern that residues of MG continue to be detected in farmed trout.