Safety and efficacy of a feed additive consisting of ethoxyquin (6‐ethoxy‐1,2‐dihydro‐2,2,4‐trimethylquinoline) for all animal species (FEFANA asbl)
2022; Wiley; Volume: 20; Issue: 3 Linguagem: Inglês
10.2903/j.efsa.2022.7166
ISSN1831-4732
AutoresVasileios Bampidis, Giovanna Azimonti, Maria de Lourdes Bastos, Henrik Christensen, Birgit Dusemund, Mojca Fašmon Durjava, Maryline Kouba, Marta López‐Alonso, Secundino López Puente, Francesca Marcon, Baltasar Mayo, Alena Pechová, Mariana Petkova, Fernando Ramos, Yolanda Sanz, Roberto Edoardo Villa, Ruud Woutersen, Antonio Finizio, Ivana Teodorović, Gabriele Aquilina, Georges Bories, Jürgen Gropp, Carlo Nebbia, Jordi Tarrés‐Call, Matteo Lorenzo Innocenti,
Tópico(s)Vitamin K Research Studies
ResumoEFSA JournalVolume 20, Issue 3 e07166 Scientific OpinionOpen Access Safety and efficacy of a feed additive consisting of ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) for all animal species (FEFANA asbl) EFSA Panel on Additives, Products or Substances used in Animal Feed (FEEDAP), Corresponding Author EFSA Panel on Additives, Products or Substances used in Animal Feed (FEEDAP) feedap@efsa.europa.eu Correspondence:feedap@efsa.europa.euSearch for more papers by this authorVasileios Bampidis, Vasileios BampidisSearch for more papers by this authorGiovanna Azimonti, Giovanna AzimontiSearch for more papers by this authorMaria de Lourdes Bastos, Maria de Lourdes BastosSearch for more papers by this authorHenrik Christensen, Henrik ChristensenSearch for more papers by this authorBirgit Dusemund, Birgit DusemundSearch for more papers by this authorMojca Fašmon Durjava, Mojca Fašmon DurjavaSearch for more papers by this authorMaryline Kouba, Maryline KoubaSearch for more papers by this authorMarta López-Alonso, Marta López-AlonsoSearch for more papers by this authorSecundino López Puente, Secundino López PuenteSearch for more papers by this authorFrancesca Marcon, Francesca MarconSearch for more papers by this authorBaltasar Mayo, Baltasar MayoSearch for more papers by this authorAlena Pechová, Alena PechováSearch for more papers by this authorMariana Petkova, Mariana PetkovaSearch for more papers by this authorFernando Ramos, Fernando RamosSearch for more papers by this authorYolanda Sanz, Yolanda SanzSearch for more papers by this authorRoberto Edoardo Villa, Roberto Edoardo VillaSearch for more papers by this authorRuud Woutersen, Ruud WoutersenSearch for more papers by this authorAntonio Finizio, Antonio FinizioSearch for more papers by this authorIvana Teodorovic, Ivana TeodorovicSearch for more papers by this authorGabriele Aquilina, Gabriele AquilinaSearch for more papers by this authorGeorges Bories, Georges BoriesSearch for more papers by this authorJurgen Gropp, Jurgen GroppSearch for more papers by this authorCarlo Nebbia, Carlo NebbiaSearch for more papers by this authorJordi Tarrés-Call, Jordi Tarrés-CallSearch for more papers by this authorMatteo Innocenti, Matteo InnocentiSearch for more papers by this author EFSA Panel on Additives, Products or Substances used in Animal Feed (FEEDAP), Corresponding Author EFSA Panel on Additives, Products or Substances used in Animal Feed (FEEDAP) feedap@efsa.europa.eu Correspondence:feedap@efsa.europa.euSearch for more papers by this authorVasileios Bampidis, Vasileios BampidisSearch for more papers by this authorGiovanna Azimonti, Giovanna AzimontiSearch for more papers by this authorMaria de Lourdes Bastos, Maria de Lourdes BastosSearch for more papers by this authorHenrik Christensen, Henrik ChristensenSearch for more papers by this authorBirgit Dusemund, Birgit DusemundSearch for more papers by this authorMojca Fašmon Durjava, Mojca Fašmon DurjavaSearch for more papers by this authorMaryline Kouba, Maryline KoubaSearch for more papers by this authorMarta López-Alonso, Marta López-AlonsoSearch for more papers by this authorSecundino López Puente, Secundino López PuenteSearch for more papers by this authorFrancesca Marcon, Francesca MarconSearch for more papers by this authorBaltasar Mayo, Baltasar MayoSearch for more papers by this authorAlena Pechová, Alena PechováSearch for more papers by this authorMariana Petkova, Mariana PetkovaSearch for more papers by this authorFernando Ramos, Fernando RamosSearch for more papers by this authorYolanda Sanz, Yolanda SanzSearch for more papers by this authorRoberto Edoardo Villa, Roberto Edoardo VillaSearch for more papers by this authorRuud Woutersen, Ruud WoutersenSearch for more papers by this authorAntonio Finizio, Antonio FinizioSearch for more papers by this authorIvana Teodorovic, Ivana TeodorovicSearch for more papers by this authorGabriele Aquilina, Gabriele AquilinaSearch for more papers by this authorGeorges Bories, Georges BoriesSearch for more papers by this authorJurgen Gropp, Jurgen GroppSearch for more papers by this authorCarlo Nebbia, Carlo NebbiaSearch for more papers by this authorJordi Tarrés-Call, Jordi Tarrés-CallSearch for more papers by this authorMatteo Innocenti, Matteo InnocentiSearch for more papers by this author First published: 03 March 2022 https://doi.org/10.2903/j.efsa.2022.7166 Requestor: European Commission Question numbers: EFSA-Q-2016-00267, EFSA-Q-2018-00013, EFSA-Q-2018-00372, EFSA-Q-2021-00523 Panel members: Vasileios Bampidis, Giovanna Azimonti, Maria de Lourdes Bastos, Henrik Christensen, Birgit Dusemund, Mojca Fašmon Durjava, Maryline Kouba, Marta López-Alonso, Secundino López Puente, Francesca Marcon, Baltasar Mayo, Alena Pechová, Mariana Petkova, Fernando Ramos, Yolanda Sanz, Roberto Edoardo Villa and Ruud Woutersen. Declarations of interest: The declarations of interest of all scientific experts active in EFSA’s work are available at https://ess.efsa.europa.eu/doi/doiweb/doisearch. Acknowledgements: The Panel wishes to thank the following for the support provided to this scientific output: Andreas Focks, Jaume Galobart, Paola Manini, Jordi Ortuño, Fabiola Pizzo, Maria Vittoria Vettori Adopted: 27 January 2021 AboutSectionsPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Ethoxyquin is synthetised from p-phenetidine, a possible mutagen, which remains in the additive as an impurity at concentrations of < 2.5 mg/kg additive. Ethoxyquin is considered safe for all animal species at the proposed inclusion level of 50 mg/kg complete feed. However, owing the presence of p-phenetidine, no safe level of the additive in feed for long-living and reproductive animals could be identified. The FEEDAP Panel derived a health-based guidance value of 0.006 mg ethoxyquin dimer (EQDM)/kg bw per day and applied it to the sum of ethoxyquin and its transformation products. A maximum total concentration of 50 mg ethoxyquin/kg complete feed for all animal species, except dairy ruminants, would not pose a risk for the consumer. However, in the absence of data on p-phenetidine residues in tissues and products of animal origin, no conclusion on the safety for the consumer could be drawn. The conclusions on consumer safety assume that the maximum total concentration of 50 mg EQ/kg feed is expressed as the sum of EQ, EQDM, EQI and DHEQ. Exposure of the unprotected user to p-phenetidine via inhalation should be minimised. No safety concerns for groundwater are expected. It is not possible to conclude on the safety of EQ for the terrestrial compartment. A risk for the aquatic compartment cannot be excluded when ethoxyquin is used in terrestrial animals. Unacceptable risk is not expected for freshwater sediment-dwelling organisms. A risk of secondary poisoning via the terrestrial food chain is not expected, whereas a risk via the aquatic food chain cannot be excluded. No concerns for aquatic organisms are expected for ethoxyquin used in fish farmed in land-based system, a risk cannot be excluded for marine sediment dwelling organisms when ethoxyquin is used in sea-cages. Ethoxyquin is considered efficacious in the range 25–50 mg/kg complete feed. Summary Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on ethoxyquin for all animal species. Ethoxyquin (EQ) is synthetised from p-phenetidine, a recognised possible mutagen, which remains in the additive as an impurity, at concentrations of < 2.5 mg/kg additive. As a conclusion from tolerance studies, EQ at the proposed inclusion level of 50 mg/kg complete feed could be considered safe for chickens for fattening, laying hens, piglets, cattle for fattening and salmon. This conclusion could be extrapolated to all animal species and categories with the exception of cats, for which the Panel cannot conclude on a safe level. However, considering that the additive contains p-phenetidine, a possible mutagen, the Panel cannot conclude on the safety of EQ at any level for long-living and reproductive animals. The FEEDAP Panel derived a health-based guidance value (HBGV) of 0.006 mg ethoxyquin dimer (EQDM)/kg body weight (bw) per day applying an uncertainty factor of 200 (taking into account the additional UF of 2 for extrapolation from subchronic to chronic study duration in rodents) to the benchmark dose (BMD) lower confidence limit for a benchmark response of 10% (BMDL10) of 1.1 mg EQDM/kg bw per day for microvesicular steatosis in liver of mice, and applied this HBGV for EQDM for the sum of EQ and its transformation products TPs (i.e. ethoxyquin dimer (EQDM), ethoxyquin quinone imine (EQI) and dihydro ethoxyquin (DHEQ) and metabolite A). Based on the European consumption data and residues in tissues and eggs (milk data not available) of food-producing animals, the exposure of the consumer to EQ, EQDM, EQI, DHEQ and metabolite A would not exceed 80% of the HBGV. Therefore, the use of EQ at a maximum total concentration of 50 mg/kg in complete feed for all animal species, except dairy animals, would not result in residues of EQ or its metabolites/transformation products which would pose a risk for the consumer. In the absence of residue data in milk, the Panel cannot conclude on the safety of EQ when used in feed for milk-producing animals. Owing the presence in the additive of p-phenetidine, and in the absence of data on the residues of p-phenetidine in tissues and products of animal origin, no conclusion on the safety of the consumer could be drawn. The conclusions on consumer safety are based on the assumption that the maximum total concentration of 50 mg EQ/kg feed is expressed as the sum of EQ, EQDM, EQI and DHEQ. Exposure of the unprotected user to p-phenetidine via inhalation cannot be excluded. The Panel concludes that, to reduce the risk, the exposure of the users should be minimised. Regarding the safety for the environment, no safety concerns for groundwater are expected. Ecotoxicity data on three additional terrestrial plants would be needed to conclude on the safety of EQ for the terrestrial compartment. A risk for the aquatic compartment cannot be excluded when the additive is used in terrestrial animals. Unacceptable risk is not expected for freshwater sediment-dwelling organisms. Ethoxyquin is considered not to pose a risk of secondary poisoning via the terrestrial food chain, whereas a risk for secondary poisoning via the aquatic food chain cannot be excluded. Ethoxyquin, when used in fish farmed in land-based system, is considered not to raise safety concerns for aquatic organisms. A risk cannot be excluded for ethoxyquin used in sea-cages for marine sediment-dwelling organisms. Ethoxyquin is considered an efficacious antioxidant in the range of 25–50 mg/kg complete feed. 1 Introduction 1.1 Background and Terms of Reference Ethoxyquin is a technological additive belonging to the functional group of antioxidants. In 2015 the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) adopted an opinion on the safety and efficacy of ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) for all animal species (EFSA FEEDAP Panel, 2015) in which it was concluded that: “Ethoxyquin itself is not genotoxic or carcinogenic and does not cause developmental toxicity. The lowest NOAEL (based on studies in rats and dogs) is 2 mg/kg body weight per day. The genotoxic profile of the dimer reflects that of ethoxyquin. Ethoxyquin quinone imine shows structural alerts for mutagenicity, carcinogenicity and DNA binding; no conclusion on the absence of genotoxicity of ethoxyquin quinone imine is possible. p-Phenetidine is a recognised possible mutagen. Concentrations of 50 mg ethoxyquin/kg and 11 mg ethoxyquin/kg complete feed might be considered as potentially safe for chickens and breeders and for dogs, respectively. No conclusion on potential safe levels for other poultry, pigs, ruminants, fish and cats is possible. Overall, when considering the presence of p-phenetidine in the additive, no conclusion on any safe level of the additive for target animals can be drawn. An assessment of safety for the consumer is prevented by the lack of exposure data, the absence of a safe level of exposure and the presence of p-phenetidine in ethoxyquin. […] No conclusion on the safety for the environment can be made. Ethoxyquin is a potent antioxidant; however, no data confirm its efficacy at the proposed use level.” The European Food Safety Authority (EFSA) received four mandates from the European Commission to complete the assessment of the safety and efficacy of ethoxyquin, based on the additional data provided by the applicant in four different submissions. The four mandates are reported below. First mandate (EFSA-Q-2016-00267) Regulation (EC) No 1831/200311 Regulation (EC) No 1831/2003 of the European Parliament and of the Council of 22 September 2003 on additives for use in animal nutrition. OJ L 268, 18.10.2003, p. 29. establishes rules governing the authorisation of additives for use in animal nutrition and, in particular, Article 9 defines the terms of such authorisation by the Commission. The applicant, ANTOXIAC EEIG/FEFANA asbl, is seeking an authorisation of ethoxyquin to be used as a feed additive (Table 1). Table 1. Description of the substance Category of additive Technological additives Functional group of additive Antioxidants Description Ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) Target animal category All animal species Applicant ANTOXIAC EEIG, FEFANA asbl (EU Feed Additives & Premixture Association) Type of request New opinion On 11 March 2016, the Commission and the European Food Safety Authority (“Authority”) have received from the applicant the “final report of the Micronucleus test in Bone Marrow cells of the mouse with 2,2,4-trimethylquinolin-6-one”. In the view of the above, the Commission requests the authority to assess the additional data submitted by the applicant in order to deliver a new opinion on the safety and efficacy of ethoxyquin as a feed additive under the conditions of Regulation (EC) No 1831/2003. Second mandate (EFSA-Q-2018-00013) Regulation (EC) No 1831/2003 establishes rules governing the authorisation of additives for use in animal nutrition and, in particular, Article 9 defines the terms of such authorisation by the Commission. In accordance with article 10(2) of Regulation (EC) No 1831/2003 in conjunction with article 7 thereof, an application was submitted on 21 September 2010 for the authorisation of ethoxyquin as a feed additive for all animal species, requesting the additive to be classified in the category “technological additives”. That application was accompanied by the particulars and documents required under Article7(3) of Regulation (EC) No 1831/2003 (Table 2). Table 2. Description of the substance Category of additive Technological additives Functional group of additive Antioxidants Description Ethoxyquin Target animal category All animal species Applicant FEFANA asbl Type of request New opinion On 21 October 2015, the Panel on Additives and Products or Substances used in Animal Feed of the European Food Safety Authority (“Authority”), stated that the assessment of the particulars and documents submitted by the applicant makes it impossible to conclude on the safety of the additive ethoxyquin for any target animals, for consumers and for the environment. This is due to an overall lack of data submitted to assess the exposure and the safety of ethoxyquin for the animals, consumers and the environment. In particular, no conclusion is possible on the absence of genotoxicity of one of the metabolites of the additive ethoxyquin, ethoxyquin quinone imine. In addition, p-phenetidine, an impurity of the additive ethoxyquin, is recognised as a possible mutagen. The Authority considered the additive ethoxyquin as a potent antioxidant in feed but efficacy at the proposed use level, which has been reduced as compared with the currently authorised maximum content in feed, could not be confirmed by the submitted data. The authority also verified the report of the method of analysis of the feed additive in feed submitted by the reference Laboratory set up by Regulation (EC) No 1831/2003. According to the Commission Implementing Regulation suspending the authorisation of ethoxyquin as a feed additive for all animal species and categories the applicant committed itself to produce supplementary data according to a time schedule listing in order of priority the studies to be carried out successively and planning that the outcome of the last of them would be available by July 2018. The set of new data have been sent to the Commission and EFSA on 15 December 2017. In view of the above, the Commission asks the Authority to deliver a new opinion for ethoxyquin to be used as a technological additive for all animal species based on the additional data submitted by the applicant. Third mandate (EFSA-Q-2018-00372) Regulation (EC) No 1831/2003 establishes rules governing the authorisation of additives for use in animal nutrition and, in particular, Article 9 defines the terms of such authorisation by the Commission. The applicant, FEFANA asbl, is seeking a Community authorisation of ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) as a feed additive to be used as an antioxidant for all animal species (Table 3). Table 3. Description of the substance Category of additive Technological additives Functional group of additive Antioxidants Description Ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) Target animal category All animal species Applicant FEFANA ASBL Type of request New opinion On 21 October 2015, the Panel on Additives and Products or Substances used in Animal Feed of the European Food safety Authority (“Authority”), stated in its opinion that the assessment of the particulars and documents submitted by the applicant makes it impossible to conclude on the safety of the additive ethoxyquin for any target animals, for consumers and for the environment. This is due to an overall lack of data submitted to assess the exposure and the safety of ethoxyquin for the animals, consumers and the environment. In particular, no conclusion is possible on the absence of genotoxicity of one of the metabolites of the additive ethoxyquin, ethoxyquin quinone imine. In addition, p-phenetidine, an impurity of the additive ethoxyquin, is recognised as a possible mutagen. The Commission gave the possibility to the applicant to submit complementary information in order to complete the assessment and to allow a revision of the Authority’s opinion. The new data have been received on 20 April 2018. In view of the above, the Commission asks the Authority to deliver a new opinion on ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) as a feed additive for all animal species based on the additional data submitted by the applicant. Fourth mandate (EFSA-Q-2021-00523) Regulation (EC) No 1831/2003 establishes rules governing the Community authorisation of additives for animal nutrition and, in particular, Article 9 defines the terms of the authorisation by the Commission. In accordance with Article 10(2) of Regulation (EC) No 1831/2003 in conjunction with Article 7 thereof, an application was submitted on 21 September 2010 for the authorisation of ethoxyquin as a feed additive for all animal species, requesting the additive to be classified in the category "technological additives". That application was accompanied by the particulars and documents required under Article 7(3) of Regulation (EC) No 1831/2003. (Table 4). Table 4. Description of the substance Category of additive Technological additives Functional group of additive Antioxidants Description Ethoxyquin Target animal category all animal species Applicant FEFANA ASBL Type of request New opinion On 21 October 2015, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) of the European Food Safety Authority (EFSA), in its opinion on the safety and efficacy of the product could not conclude on the safety and efficacy of the additive. Under Regulations (EU) 2017/962 and 2021/412, the Commission gave the possibility to the applicant to submit supplementary information and data in order to complete the assessment and to allow a revision of the EFSA’s opinion. The new data have been received on 23 June 2021 and sent directly to EFSA by the applicant. In view of the above, the Commission asks EFSA to deliver a new opinion on ethoxyquin as a feed additive for all animal species based on the supplementary data submitted by the applicant, in accordance with Article 29(1)(a) of Regulation (EC) No 178/2002. 1.2 Additional information The additive ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) was authorised in the EU for use as a technological additive (functional group: antioxidants) in all animal species and categories until 7 June 2017.22 Commission Implementing Regulation (Eu) 2017/962 of 7 June 2017 suspending the authorisation of ethoxyquin as a feed additive for all animal species and categories OJ L 145, 8.6.2017, p. 13. Ethoxyquin was also authorised in the EU as pesticide until 2009, when the authorisation for its use was withdrawn.33 Commission Decision 2008/941/EC of 8 December 2008 concerning the non-inclusion of certain active substances in Annex I to Council Directive 91/414/EEC and the withdrawal of authorisations for plant protection products containing these substances. OJ L 335, 13.12.2008, p. 91. It is a legal requirement of the United Nations International Maritime Organisation (IMO) that ‘Stabilization of fishmeal shall be achieved to prevent spontaneous combustion by effective application: of between 400 and 1,000 mg/kg ethoxyquin or liquid BHT (butylated hydroxy toluene); or between 1,000 and 4,000 mg/kg BHT in powder form at the time of production’ (IMO, 2014) and that: ‘fish scrap of fish meal shall contain at least 100 ppm of antioxidant (ethoxyquin) at the time of consignment’ (UN, 2014). The Scientific Committee on Animal Nutrition (SCAN) issued an opinion on the safety of ethoxyquin for dogs (EC, 1993). In 2015, the FEEDAP Panel adopted an opinion on the safety and efficacy of ethoxyquin (6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) for all animal species (EFSA FEEDAP Panel, 2015). The Scientific Committee for Food (SCF) issued an opinion on the safety of ethoxyquin used for the treatment of scald in apples and pears (EC, 1975). The Joint Meeting of the FAO Panel of Experts on Pesticide Residues in Food and the Environment (JMPR) has delivered several opinions on the safety of ethoxyquin (FAO, 1969, 1998, 2005). EFSA issued a conclusion on the peer review of the pesticide risk assessment of ethoxyquin (EFSA, 2010) and a reasoned opinion on the review of the existing maximum residue levels (MRLs) for ethoxyquin (EFSA, 2013). 2 Data and methodologies 2.1 Data The present assessment is based on data submitted by the applicant in the form of additional information44 FEED dossier references: FAD-2016-0018, FAD-2017-0073, FAD-2018-0029, EFSA-Q-2021-00527. to a previous application of the same product.55 FEED dossier reference: FAD-2010-0141. The FEEDAP Panel used the data provided by the applicant together with data from other sources, such as previous risk assessments by EFSA or other expert bodies, peer-reviewed scientific papers and other scientific reports to deliver the present output. 2.2 Methodologies The approach followed by the FEEDAP Panel to assess the safety and the efficacy of ethoxyquin is in line with the principles laid down in Regulation (EC) No 429/200866 Commission Regulation (EC) No 429/2008 of 25 April 2008 on detailed rules for the implementation of Regulation (EC) No 1831/2003 of the European Parliament and of the Council as regards the preparation and the presentation of applications and the assessment and the authorisation of feed additives. OJ L 133, 22.5.2008, p. 1. and the relevant guidance documents: Guidance on technological additives (EFSA FEEDAP Panel, 2012a), Technical guidance: Tolerance and efficacy studies in target animals (EFSA FEEDAP Panel, 2011), Technical Guidance for assessing the safety of feed additives for the environment (EFSA, 2008a, revised in 2009), Guidance for the preparation of dossiers for the re-evaluation of certain additives already authorised under Directive 70/524/EEC (EFSA, 2008b, revised in 2009), Guidance for the preparation of dossiers for additives already authorised for use in food (EFSA FEEDAP Panel, 2012b), Guidance for establishing the safety of additives for the consumer (EFSA FEEDAP Panel, 2012c), Guidance on studies concerning the safety of use of the additive for users/workers (EFSA FEEDAP Panel, 2012d), Guidance on the assessment of the safety of feed additives for the environment (EFSA FEEDAP Panel, 2019). 3 Assessment Ethoxyquin (EQ) is intended to be used as a technological additive (functional group: antioxidants). In its previous opinion (EFSA FEEDAP Panel, 2015), the FEEDAP Panel could not conclude on the safety of the additive for the target animals, the consumer and the environment and on its efficacy. The applicant submitted additional information in order to allow a conclusion on the safety and efficacy of EQ to be reached. In this context, the applicant modified the specifications of the additive, in particular by reducing the content of p-phenetidine. 3.1 Characterisation The additive ethoxyquin is synthetised by the reaction of p-phenetidine and acetone. The starting material p-phenetidine, a recognised possible mutagen, remains in the additive as an impurity. In the previous applications, the additive was specified as ‘> 91% EQ, not more 8% of ethoxyquin polymers, ≤ 3% p-phenetidine and ≤ 0.02% acetone’. In the current submission, the applicant has modified the specifications to reduce the content of p-phenetidine. The applicant, with the aim to better characterise the additive, performed a ring trial comparing different methods of analysis (titration, gas chromatography with flame ionisation detection (GC-FID) or high-performance liquid chromatography with ultraviolet detection (HPLC-UV)) and analysing different batches of ethoxyquin from three producers (three batches each).77 FAD-2017-0073/Technical dossier/Annex 01. Based on the results of the ring trial, the applicant proposed the following specifications for the additive ethoxyquin: Ethoxyquin > 96% w/w (determined by titration); ethoxyquin monomer > 92% determined by (GC-FID); ethoxyquin-related substances < 7% (GC-FID)88 The sum of eight ethoxyquin related impurities (including EQDM).; p-phenetidine < 2.5 mg/kg (GC-FID, corresponding to 0.00025%); ethoxyquin quinone imine < 0.09% (GC-FID). The analysis of six pilot batches of the additive prepared by two producers (three batches each) was analysed using the above-described methods.99 FAD-2017-0073/Technical dossier/Annex 06. The results showed that the pilot batches of the additive comply with the newly proposed specifications; in particular, the content of p-phenetidine was on average 1.7 mg/kg (range: 0.5–2.3 mg/kg). 3.1.1 Stability Antioxidants are by essence unstable chemicals degraded progressively during feed protection and converted by oxidation to other chemical structures (transformation products (TPs)), sometimes endowed of antioxidative properties also (e.g. 1,8’-ethoxyquin dimer (1,8’-EQDM, further referred as EQDM), ethoxyquin quinone imine (EQI) and dihydro ethoxyquin (DHEQ)). The genesis of TPs in feeds is highly variable, depending on many physical and chemical parameters associated with the composition and to the technological treatments of the feed. The more sensitive analytical methods used in the newly submitted studies, with an increased capacity of structural elucidation, enlarge to a considerable extent the spectrum of EQ TPs formerly described (EFSA FEEDAP Panel, 2015). The structural formulas of EQ and its main TPs described in the stability studies is reported in Figure 1. The applicant provided two stability studies, also aiming to identify EQ TPs in premixtures and compound feed. Figure 1Open in figure viewerPowerPoint Structural formula of ethoxyquin (EQ) and the main transformation products (TPs) identified in in feed and tissues of target species: dihydro ethoxyquin (DHEQ), ethoxyquin quinone imine (EQI), (DHMEQ) and 1,8’-ethoxyquine dimer (1,8’-EQDM) EQ persistence in premixtures One batch of a vitamin/mineral premixture was supplemented with 5% EQ, one from each of the three producers. The samples were kept at 25°C, 60% relative humidity (RH) or at 45°C, 75% RH for 90 days.1010 FAD-2017-0073/Technical dossier/Annex 07. EQ and related degradation products EQI, DHMEQ and EQDM were analysed.1111 By HPLC-UV/Vis with detector set at 220, 249 and 375 nm, using their corresponding relative response factors. About 50% EQ disappeared after 90 days at 25°C. A similar decline occurred already after 8 days at 40°C. The sum of EQ and related degradation products amounted to about 85% and 25% of the initial EQ content after
Referência(s)