SCIENTIFIC OPINION ADOPTED: 8 September 2015 PUBLISHED: 29 September 2015 doi:10.2903/j.efsa.2015.4242 Abstract Safety assessment of the substance 2,4-di-tert-amylphenol, impurity and hydrolysis product of the substance phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters, for use in food contact materials EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF Panel) deals with the safety assessment of 2,4-di-tert-amylphenol, an impurity and hydrolysis product of the antioxidant phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters evaluated in 2011 by the CEF Panel for its uses in all polymers intended for contact with all food types under any time/temperature conditions. Migration of 2,4-di-tert-amylphenol from linear low-density polyethylene made with the antioxidant was not detected in 3 % acetic acid and water, and was up to 0.1 mg/kg in olive oil. Based on previous considerations and the negative results in two new in vitro genotoxicity tests, the Panel concluded that there is no evidence that 2,4-di-tert-amylphenol has any genotoxic potential. Based on a 90-day oral toxicity study in rats, a no observed adverse effect level (NOAEL) of 5 mg/kg body weight per day was determined. Considering the metabolism of branched chain alkylphenols and remaining uncertainty related to the potential for accumulation in man, an extra factor of 3 was considered along with the default uncertainty factor of 100. By applying the resulting uncertainty factor of 300 to the NOAEL, the migration of 2,4-di-tert-amylphenol should not exceed 1 mg/kg food. The CEF Panel concluded that the substance 2,4-di-tert-amylphenol does not give rise to safety concerns for the consumer if its migration does not exceed 1 mg/kg food and it is included in the current 5 mg/kg food restriction for the substance phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1- dimethylpropyl)phenyl triesters, expressed as the sum of the phosphite and phosphate forms of the substance and 4-tert-amylphenol. European Food Safety Authority, 2015 Keywords: 2,4-di-tert-amylphenol, phosphorous acid mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters, food contact materials, safety assessment Requestor: Food Standards Agency, United Kingdom Question number: EFSA-Q-2015-00091 Correspondence: fip@efsa.europa.eu www.efsa.europa.eu/efsajournal EFSA Journal 2015;13(9):4242
Panel members: Claudia Bolognesi, Laurence Castle, Jean-Pierre Cravedi, Karl-Heinz Engel, Paul Fowler, Roland Franz, Konrad Grob, Rainer Gürtler, Trine Husøy, Sirpa Kärenlampi, Wim Mennes, Maria Rosaria Milana, André Penninks, Vittorio Silano, Andrew Smith, Maria de Fátima Tavares Poças, Christina Tlustos, Fidel Toldrá, Detlef Wölfle, Holger Zorn and Corina-Aurelia Zugravu. Acknowledgements: The Panel wishes to thank the members of the Working Group on Food Contact Materials: Claudia Bolognesi, Laurence Castle, Jean-Pierre Cravedi, Riccardo Crebelli, Roland Franz, Konrad Grob, Martine Kolf-Clauw, Eugenia Lampi, Maria Rosaria Milana, Maria de Fátima Tavares Poças, Kettil Svensson and Detlef Wölfle, and EFSA staff member: Eric Barthélémy for the preparatory work on this scientific output. Suggested citation: EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on the safety assessment of the substance 2,4-di-tertamylphenol, impurity and hydrolysis product of the substance phosphorous acid, mixed 2,4-bis(1,1- dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters, for use in food contact materials. EFSA Journal 2015;13(9):4242, 8 pp. doi:10.2903/j.efsa.2015.4242 ISSN: 1831-4732 European Food Safety Authority, 2015 Reproduction is authorised provided the source is acknowledged. The EFSA Journal is a publication of the European Food Safety Authority, an agency of the European Union. www.efsa.europa.eu/efsajournal 2 EFSA Journal 2015;13(9):4242
Table of contents Abstract... 1 1. Introduction... 4 1.1. Background and Terms of Reference as provided by the requestor... 4 2. Data and methodologies... 4 2.1. Methodologies... 4 2.2. Data... 5 3. Assessment... 5 3.1. General information... 5 3.2. Non-toxicity data... 5 3.3. Toxicological data... 6 4. Conclusions... 7 Documentation provided to EFSA... 7 References... 7 Abbreviations... 8 www.efsa.europa.eu/efsajournal 3 EFSA Journal 2015;13(9):4242
1. Introduction 1.1. Background and Terms of Reference as provided by the requestor Before a substance is authorised to be used in food contact materials and is included in a positive list, EFSA s opinion on its safety is required. This procedure has been established in Articles 8 and 9 of Regulation (EC) No 1935/2004 1 of the European Parliament and of the Council of 27 October 2004 on materials and articles intended to come into contact with food. According to this procedure industry submits applications to the Member States competent Authorities which transmit the applications to EFSA for their evaluation. In this case, EFSA received an application from the Food Standards Agency, United Kingdom, requesting the evaluation of the substance 2,4-di-tert-amylphenol (CAS number 120-95-6), impurity and hydrolysis product of the substance phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters (CAS number 939402-02 and food contact material (FCM) substance No 974). The dossier was submitted on behalf of Addivant. According to Regulation (EC) No 1935/2004 of the European Parliament and of the Council on materials and articles intended to come into contact with food EFSA is asked to carry out an assessment of the risks related to the intended use of the substance and to deliver a scientific opinion. 2. Data and methodologies 2.1. Methodologies Regulation (EC) No 1935/2004 on materials and articles intended to come into contact with food foresees that EFSA will publish guidelines on its risk assessment process and the corresponding data requirements from applicants. The regulation also underlines that, pending the publication of such EFSA guidelines, applicants may consult the guidelines of the Scientific Committee on Food (SCF). The SCF guidelines date back to 2001 (EC, 2001) and have been used since 2003 by the former AFC Panel (EFSA Panel on food additives, flavourings, processing aids and materials in contact with food) and by the CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), which succeeded the AFC. The methodology is based on the characterisation of the substance that is the object of the request for safety assessment prior to authorisation, its impurities and reaction and degradation products, the evaluation of exposure to those substances through migration, and the definition of the minimum sets of toxicity data required for safety assessment. To establish the safety from ingestion of migrating substances, the toxicological data indicating the potential hazard and the likely human exposure data need to be combined. As human exposure data were not available in 2001 and not yet used, exposure has been estimated from studies on migration into food or food simulants taking into account the fact that a person may consume daily up to 1 kg of food in contact with the relevant food contact material. As a general rule, the greater the exposure through migration, the more toxicological data are required for the safety assessment of a substance. Currently there are three tiers with different thresholds triggering the need for more toxicological information as follows: 1) In the case of high migration (i.e. 5 60 mg/kg/food), an extensive dataset is needed. 2) In the case of migration between 0.05 and 5 mg/kg food, a reduced dataset may suffice. 3) In the case of low migration (i.e. < 0.05 mg/kg food), only a limited dataset is needed. 1 Regulation (EC) No 1935/2004 of the European Parliament and of the Council of 27 October 2004 on materials and articles intended to come into contact with food and repealing Directives 80/590/EEC and 89/109/EEC. OJ L 338, 13.11.2004, p. 4 17. www.efsa.europa.eu/efsajournal 4 EFSA Journal 2015;13(9):4242
More details of the required data are available in the SCF guidelines (EC, 2001). 2.2. Data The studies submitted for evaluation followed the SCF guidelines for the presentation of an application for a safety assessment of a substance to be used in food contact materials prior to its authorisation (EC, 2001). Non-toxicity data Data on identity Data on physical and chemical properties Data on intended use and authorisation Data on migration of the substance and hydrolysis products Data on residual content of the substance Toxicity data Bacterial gene mutation test In vitro mammalian chromosome aberration test Ninety-day oral toxicity study in rats 3. Assessment 3.1. General information The substance 2,4-di-tert-amylphenol is an impurity and also a hydrolysis product of the substance phosphorous acid mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters which was evaluated for its use as an antioxidant in all polymers by the CEF Panel in 2011 (EFSA CEF Panel, 2011). The CEF Panel concluded that the substance phosphorous acid, mixed 2,4-bis(1,1- dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters be classified with a restriction of 5 mg/kg food (expressed as the sum of the phosphite and phosphate forms of the substance and the hydrolysis product 4-tert-amylphenol). The Panel also concluded that migration of the hydrolysis product 2,4-di-tert-amylphenol should not exceed 0.05 mg/kg food. In this application, the applicant requests a re-evaluation of the specific migration limit (SML) for 2,4-di-tert-amylphenol, currently established at 0.05 mg/kg food, with a view to it being included within the overall SML of 5 mg/kg that currently applies to the sum of the phosphite and phosphate forms of the antioxidant and the hydrolysis product 4-tert-amylphenol. 3.2. Non-toxicity data Chemical formula: C 16 H 26 O Figure 1: Chemical structure of 2,4-di-tert-amylphenol 2,4-di-tert-Amylphenol is found as an impurity in the substance phosphorous acid, mixed 2,4-bis(1,1- dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters and it can also be produced as a hydrolysis product of that antioxidant following migration into aqueous media. Its molecular weight is 234.4 Da and its log P o/w is 6.31. www.efsa.europa.eu/efsajournal 5 EFSA Journal 2015;13(9):4242
Specific migration tests were performed using linear low-density polyethylene (LLDPE) test samples containing the antioxidant (sum of the phosphite and phosphate forms) at 1 336 mg/kg. Specific migration tests were carried out in contact with the food simulants 3 % acetic acid, water and olive oil, which in this case are appropriate for intended contact with all food types. The migration test conditions were 2 hours at 100 ºC followed by 10 days at 40 ºC. Prior to migration testing, stability of the antioxidant in these three simulants was assessed under the migration test conditions by measuring the extent of hydrolysis at the end of the two sequential test conditions. When dissolved in 3 % acetic acid and water, 70 % and 67 %, respectively, of the antioxidant undergoes hydrolysis. In 3 % acetic acid, the antioxidant is mostly hydrolysed into 4-tert-amylphenol (para-tert-amylphenol; PTAP) (log P o/w = 3.91) and the intermediate P(DTAP)(OH) 2 and to a minor extent into 2,4-di-tert-amylphenol (DTAP). In water, the antioxidant is mostly hydrolysed into 4-tert-amylphenol and the intermediates P(DTAP)(OH) 2 and P(PTAP)(OH) 2 and to a minor extent into 2,4-di-tert-amylphenol. In olive oil, no hydrolysis could be observed and the antioxidant was fully converted into its oxidation form (phosphate form). In the migration tests using 3 % acetic acid and water, 2,4-di-tert-amylphenol was not detected in either of the simulants at the detection limit of 20 μg/kg. In olive oil, 2,4-di-tert-amylphenol was found at levels up to 0.1 mg/kg. However, in mixed foods, hydrolysis of migrated antioxidant might result in higher concentrations. 3.3. Toxicological data The CEF Panel had already noted in a previous opinion (EFSA CEF Panel, 2011) that there are no structural alerts for genotoxicity in 2,4-di-tert-amylphenol. In the absence of more toxicological information on this substance, a specific migration limit of 0.05 mg/kg food was allocated according to the SCF guidelines (EC, 2001). Newly performed in vitro studies on 2,4-di-tert-amylphenol demonstrate that the substance did not induce gene mutations in bacteria (Salmonella typhimurium TA1537, TA1535, TA98, TA100 and TA102) and did not induce chromosomal aberrations in human peripheral lymphocytes in the presence or absence of a metabolic activation system. Based on previous considerations and the negative results in the two in vitro tests, the Panel concluded that there is no evidence that the substance has genotoxic potential. The substance 2,4-di-tert-amylphenol was tested in a 90-day oral toxicity study in Wistar rats at doses of 0.5, 5, 20 and 80 mg/kg bw (body weight) per day. Microscopic findings at the highest dose were observed in lung (alveolar macrophage aggregation in males), kidneys (inflammatory cell infiltrates, tubular basophilia and degeneration), urinary bladder (hyperplasia/hypertrophy of the urothelium in females) and liver (scattered macrovesicular vacuolation in all males and in 8/10 females; hepatocellular hypertrophy at a minimal degree in 2/10 males). In addition, the following macroscopic findings were observed in animals treated at 20 and/or 80 mg/kg bw: an accentuated lobular pattern of the liver (five males at 80 mg/kg and two males at 20 mg/kg bw); enlargement of the liver (one male at 80 mg/kg bw); and pale discoloration of the liver (three males and one female at 80 mg/kg bw and one male at 20 mg/kg bw). Absolute liver weights were increased in males at 20 and 80 mg/kg bw (18 and 31 % respectively, P 0.05) and in females at 80 mg/kg (16 %, P 0.05). The magnitudes of the relative changes were similar. Alkaline phosphatase activity in males was increased dose-dependently (at 20 and 80 mg/kg bw per day) with statistical significance at the highest dose. Bile acid levels decreased in females (statistically significant at 20 and 80 mg/kg bw per day). Based on these findings in liver and the liver-associated effects, the no observed adverse effect level (NOAEL) is considered to be 5 mg/kg bw per day. Regarding the potential for 2,4-di-tert-amylphenol to accumulate in man, the CEF Panel considered that branched chain alkylphenols, e.g. 4-methyl-2,6-di-tert-butylphenol (butylated hydroxytoluene, BHT; EFSA ANS Panel, 2012) and 2,6-di-isopropylphenol (propofol), can be metabolised to glucuronides and/or sulphates via UGT1A9 and SULT1A (McQueen, 2010). Nevertheless, in the absence of toxicokinetic data specifically for 2,4-di-tert-amylphenol, the Panel considered it www.efsa.europa.eu/efsajournal 6 EFSA Journal 2015;13(9):4242
appropriate to apply an extra factor of 3 along with the default uncertainty factor of 100 (EFSA Scientific Committee, 2012) to the NOAEL of 5 mg/kg bw per day. Consequently, using a body weight of 60 kg and a food consumption of 1 kg per day (EC, 2001), migration of 2,4-di-tert-amylphenol up to 1 mg/kg food would not give rise to safety concerns. 4. Conclusions Having considered the above-mentioned data, the CEF Panel concluded that the substance 2,4-di-tert-amylphenol, impurity and hydrolysis product of the substance phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters, is not a safety concern for the consumer if its migration does not exceed 1 mg/kg food and it is included in the existing 5 mg/kg food restriction for the substance phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters. The restriction on the substance phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters (FCM substance no 974) could then be expressed as the sum of the phosphite and phosphate forms of the substance, 4-tert-amylphenol and 2,4-di-tert-amylphenol; in addition the migration of 2,4-di-tert-amylphenol should not exceed 1 mg/kg food. Documentation provided to EFSA 1. Technical dossier. February 2015. Submitted on behalf of Addivant. References EC (European Commission), (2001). Guidelines of the Scientific Committee on Food for the presentation of an application for safety assessment of a substance to be used in food contact materials prior its authorisation. Available online: http://ec.europa.eu/food/fs/sc/scf/out82_en.pdf (accessed 21 September 2015). EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), 2012. Scientific Opinion on the reevaluation of butylated hydroxytoluene BHT (E 321) as a food additive. EFSA Journal 2012;10(3):2588, 43 pp. doi:10.2903/j.efsa.2012.2588 EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF), 2011. Scientific Opinion on the safety evaluation of the substance, phosphorous acid, mixed 2,4-bis(1,1- dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters, CAS No. 939402-02-5, for use in food contact materials. EFSA Journal 2011;9(7):2305, 14 pp. doi:10.2903/j.efsa.2011.2305 EFSA Scientific Committee, 2012. Guidance on selected default values to be used by the EFSA Scientific Committee, Scientific Panels and Units in the absence of actual measured data. EFSA Journal 2012;10(3):2579, 32 pp. doi:10.2903/j.efsa.2012.2579 McQueen CA (editor-in-chief), 2010. Comprehensive toxicology. Volume 4, Biotransformation, 2nd edition. Ed. Guengerich FP. Elsevier, Amsterdam. www.efsa.europa.eu/efsajournal 7 EFSA Journal 2015;13(9):4242
Abbreviations AFC Panel on Additives, Flavourings, Processing Aids and Materials in Contact with Food BHT bw CEF EC DTAP FCM LLDPE NOAEL PTAP P o/w SCF SML butylated hydroxytoluene body weight Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids European Commission 2,4-di-tert-amylphenol food contact materials linear low-density polyethylene no observed adverse effect level 4-tert-amylphenol octanol/water partition coefficient Scientific Committee on Food specific migration limit www.efsa.europa.eu/efsajournal 8 EFSA Journal 2015;13(9):4242