Ethoxyquin and metabolites in fish and fish feed

Ethoxyquine (1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline) is used as a feed additive. The compound is not allowed as a plant protection agent since 2011, but it is allowed as an additive (E234) for feed. It ensures that the fats and fat-soluble vitamins in the feed do not oxidize. The feed will not be so fast rancid. For this reason, fish from aquaculture are often contaminated with the substance or with their metabolites. Originally the substance was used in the car industry. In the 1920s the tires were made of natural rubber and were protected with ethoxyquin before the aging. From the 1950s onwards, the chemical was also used for feedingstuffs. There are currently no legal limits for fish. The NGOs are looking at the maximum residue level of meat to estimate.