Ethoxyquin (E324) is a synthetic antioxidant that is used primarily in animal feed (such as aquaculture and pet food). Globally, ethoxyquin is not approved for use as a direct food additive in foods for human consumption; therefore, ethoxyquin should not be detectable in the food supply. Specific to the omega-3 industry, some krill meals and crude fish oils for animal feed are preserved using ethoxyquin. As the use of ethoxyquin is so controversial, some omega-3 manufacturers have asked why it is used at all in sources that can supply both human and animal nutrition products.
Ethoxyquin effectively helps to reduce the risk of combustion in products such as krill or fish that are not kept frozen. The supply chains for fish and krill oil products for human consumption tend to be well segregated from each other, and the economics of animal feed products do not always justify the same types of refrigeration or other methods that are used for human consumption products, so chemical antioxidants become the only option.
Of concern recently are reports of crossover between the animal feed and human food supply chains. Although most of the cases have been limited to detection in shrimp, there is concern that it could spread to omega-3 oils produced from farmed seafood sources. Recently, the Australian Therapeutic Goods Administration (TGA) reported (RC-2014-RN-00428-1) that it had detected the presence of ethoxyquin in multiple krill oil products sponsored by a large Australian-owned manufacturer and distributor. In an effort to prevent further consumer exposure to ethoxyquin, the retail products in question were recalled, but it is a good example of why companies should be testing their omega-3 products to ensure there is no crossover from the animal feed supply chain.
Also, if companies market or source ingredients for both human and animal supply chains, you should be aware of the applicable regulations and controversy surrounding ethoxyquin because of the potential for crossover.
The European Union (EU) upper limit in feed (including fish feed, but excluding dog food) is 150ppm ethoxyquin alone or together as the sum of BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene) and ethoxyquin.1 The maximum content of ethoxyquin allowed in dog food is 100ppm and the mixture of ethoxyquin with BHA and BHT is allowed provided the total mixture doesn’t exceed 150ppm. According to the European Food Safety Authority (EFSA), ethoxyquin is “considered to be toxic to aquatic organisms based on the acute toxicity data provided for fish, daphnia and algae.”2
According to the TGA of the Australian Department of Health, the acceptable daily intake (ADI) for ethoxyquin used on food producing crops and animals is 0.001mg/kg body weight.3
Ethoxyquin was first evaluated by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) in 1969 and then again in 1998 and 2005.4–7 In 2013, EFSA concluded in its report, titled “Reasoned Opinion on the Review of the Existing Maximum Residue Levels (MRLS) for Ethoxyquin According to Article 12 of Regulation (EC) No. 396/2005,” that the Codex MRL for ethoxyquin was not adequately supported by the data and a possible risk to consumers existed.8
Although there is no specified limit for fish oil, the maximum residue limit (MRL) for fish is 1ppm.9 Until recently, the Ministry of Health, Labour and Welfare (MHLW) had imposed an unofficial MRL of 0.02ppm in crustaceans. Based on this limit, in 2012, there were 42 reported violations of the Food Sanitation Law (Article 11, Paragraph 3) with “detection over the amount unlikely to cause damage to human health.”
In 2013, the reported violations dropped to 12, perhaps because of increased enforcement during 2012. In 2014 thus far, there have been no reported violations. On 3 December 2013, as part of an upcoming revision of the standards and specifications for foods and food additives under the Food Sanitation Law, the MHLW notified the World Trade Organization (WTO) of a 0.2ppm MRL for ethoxyquin in crustaceans.10
The approved uses of ethoxyquin in animal feeds are addressed in 21 CFR 573.380 and 21 CFR 573.400, whereas established tolerances can be found in 21 CFR 172.140.11–13 When ethoxyquin is used in animal feed, it must be labelled.14 The US Environmental Protection Agency (EPA) has published a registration eligibility decision (RED) fact sheet on ethoxyquin.15
GOED encourages all businesses to verify that their omega-3 products for human consumption are free from ethoxyquin.
2. EFSA Journal 8(9), 1710 [38 pp.]: doi:10.2903/j.efsa.2010.1710 (2010).
Adam Ismail is Executive Director and Harry Rice is VP, Regulatory and Scientific Affairs at the Global Organization for EPA and DHA Omega-3s (GOED)