Ethoxyquin in feed: EU status and the antioxidants used instead

Ethoxyquin had been authorised without a time limit under Directive 70/524/EEC, for all animal species. Like the other additives of that period, it was entered in the register as an existing product, then made subject to a re-evaluation under Regulation (EC) No 1831/2003: the application was submitted on 21 September 2010.

An additive is authorised only if the applicant shows that it has no adverse effect on animal health, human health or the environment (Article 5 of the Regulation). In its opinion of 21 October 2015, then in that of 27 January 2022, issued after several sets of additional data, EFSA concluded that the data supplied did not allow this to be established.

The Commission therefore acted in two steps. In 2017 it suspended the authorisation pending further studies. In August 2022 it denied it: the denial concerns ethoxyquin as an additive in the category of technological additives, in the functional group of antioxidants.

Is ethoxyquin a pesticide, or a preservative? Ethoxyquin was also an active substance in plant protection products: Commission Decision 2011/143/EU did not include it in Annex I to Directive 91/414/EEC and required Member States to withdraw the corresponding authorisations. In feed, it was classified not as a preservative but as an antioxidant: a preservative protects feed against micro-organisms, an antioxidant against oxidation. The two groups are defined separately in the feed additive categories of Regulation 1831/2003.

Feed materials of marine origin are rich in fatty acids and highly sensitive to oxidation and heat: they have to be stabilised with an antioxidant, especially before long transport or storage. That is the finding of the suspension Regulation itself (recital 11), and it is why ethoxyquin was so widely used there.

The text therefore gave them the longest deadlines. They applied to the materials in Chapter 10 of the Catalogue of feed materials, “fish, other aquatic animals and products derived thereof”, which includes fish meal and fish oil, and to dried algae: the additive intended for those materials until 30 September 2019, the materials themselves until 31 December 2019, compound feed containing them until 31 March 2020, with three more months for use (Article 3).

Those deadlines have passed. In the Union, fish meal or fish oil stabilised with ethoxyquin has had no transitional measure to rely on since 2020, and the 2022 denial closed the file.

What to ask for a lot. Which antioxidant stabilised it, at what level, and whether it is accepted in the country where the feed will be sold. The specification of the lot and its safety data sheet say so. A material made outside the Union may have been stabilised under the rule of its country of origin: the question arises for each origin.

And check. A stabilised lot is not necessarily an intact lot: peroxide value, anisidine value and the Rancimat test do not say the same thing. The Linkatiox page explains how to read them on fish meal.

The 2017 Regulation says it itself: the other authorised antioxidants do not have the same characteristics as ethoxyquin, whether in efficacy, in the concentration needed, in duration of action or in cost, and adopting them means reformulating and adapting the process (recital 13). Ethoxyquin is therefore not replaced molecule for molecule, at the same dose. Three points are reviewed together.

• The dose. It is worked out on the fat to be protected and on how unsaturated it is, not on the tonne of feed.
• Stability through the process. Temperature and duration of conditioning, extrusion and drying: not all antioxidants withstand them in the same way.
• The label and the destination market. Each molecule is checked against the list of the country where the feed will be sold, and against the customer’s specification.

The usual approach is to combine antioxidants of different solubilities, each covering one phase of the fat, with an agent that binds copper and iron, the metals that set off the reaction. Tocopherol-rich extracts answer specifications that exclude synthetic antioxidants, most often at a higher dose.

“Ethoxyquin-free” has also become a commercial requirement: buyers write it into their specifications in markets where the rule still allows the molecule.

In every case, the result is measured. An oxidative stability test on the fat or on the feed, before and after the change, is worth more than an equivalence on paper.