Migration Of Oligomers Research Articles

Cellulose trays with PLA-based liners as single-used food packaging: Characterisation, performance and migration

In France, collective catering must adopt compostable alternatives for warming/serving trays to reduce the use of plastic materials by 2025. Cellulose trays laminated with biobased polymers such as polylactic acid are gaining popularity. To guarantee safety, the presence and the migration of substances should be tested according to established protocols. PLA, PCL, PBAT, PBS, PEG, were identified in the liners of the trays collected from the market. Testing ensured the compliance with global migration limit. After undergoing the real-condition processing, the trays experienced minor physical degradation and fractures, compromising integrity. Heating to higher temperatures (130 °C) led to some modifications of the polymer composition, and several substances linked to the safety of the trays were detected as potential migrants like plasticizers and additives (styrene and a volatile fluorinated compound) in some of the samples. Migration of monomers and oligomers from the liner should further be studied to guarantee food safety.

Migration of oligomers from Tritan™ copolyester: application of hydrolysis for overall oligomer determination

Tritan™ (a kind of glycol-modified polycyclohexylene dimethylene terephthalate) is a novel copolyester mainly in use for the production of sports bottles and food storage containers. Oligomers in three food-grade Tritan™ samples were identified after dissolution-precipitation by high performance liquid chromatography with diode array detection and mass spectrometry and quantified after alkaline hydrolysis to the monomers. The obtained overall oligomer content <1000 Da determined by hydrolysis ranged from 7.2 to 10.6 mg/g material. Three consecutive migration experiments were performed according to the Commission Regulation (EU) No 10/2011. Oligomer migration values decreased from first to third migration during all simulations. Less than 25 µg/kg (third migrate) were detected in bottle migrates when tested under room temperature storage conditions (40 °C, 24 h) with simulants 3% acetic acid, 20 and 50% ethanol and during hot-fill testing (70 °C, 2 h) with simulants 3% acetic acid and 20% ethanol, respectively, while 170 µg/kg were determined in 50% ethanol after migration at 70 °C for 2 h. Food storage containers that were labelled as microwave-suitable by the supplier were tested according to the Joint Research Centre recommendations for microwave dishware. A strong deformation of the containers as well as a loss of transparency were observed during the tests (100 °C, 2 h with 10% ethanol and 3% acetic acid in an autoclave, 121 °C, 30 min with sunflower oil), questioning the suitability of the material for microwave applications. Maximum oligomer migration was 379 µg/kg during the third migration (sunflower oil at 121 °C for 30 min). Based on the migration data and an in silico oligomer evaluation according to the threshold of toxicological concern concept, no exceedances of daily thresholds for oligomers are expected from a proper use of Tritan™ drinking bottles, even with hot drinks.

Analysis of Migrant Cyclic PET Oligomers in Olive Oil and Food Simulants Using UHPLC-qTOF-MS.

Oligomers are a particular category of non-intentionally added substances (NIAS) that may be present in food contact materials (FCMs), such as polyethylene terephthalate (PET), and consequently migrate into foods. Here, an ultra-high-pressure liquid chromatography quadruple time-of-flight mass spectrometry (UHPLC-qTOF-MS) method was developed for the analysis of 1st series cyclic PET oligomers in virgin olive oil (VOO) following a QuEChERS clean-up protocol. Oligomer migration was evaluated with two different migration experiments using bottles from virgin and recycled PET: one with VOO samples stored in household conditions for a year and one using the food simulant D2 (95% v/v ethanol in water) at 60 °C for 10 days. Calibration curves were constructed with fortified VOO samples, with the LOQs ranging from 10 to 50 µg L-1 and the recoveries ranging from 86.6 to 113.0%. Results showed no migration of PET oligomers in VOO. However, in the simulated study, significant amounts of all oligomers were detected, with the migration of cyclic PET trimers from recycled bottles being the most abundant. Additional substances were tentatively identified as linear derivatives of PET oligomers. Again, open trimer structures in recycled bottles gave the most significant signals.

Impact of toluene sorption on oligomers and antioxydants migration from HDPE pipes

The objective of this work was to investigate the ageing behaviour of filled HDPE samples, immersed into toluene at 60 °C, in terms of migration and extraction of stabilizers and oligomers. Firstly, the high level of solvent solubility (mass uptake of∼13.6 wt%), due to the high toluene/HDPE affinity allowed the oligomers (M < 450 g/mol) to migrate and to finally be extracted (3.5 wt% of the mass sample for an immersion time of 96 h). Secondly, the decrease in OIT values, measured at 200 °C on HDPE samples dried after immersion, also revealed the extraction of antioxydants. On the other hand, the impact of the introduction of spherical (ZnO) or lamellar (graphite and organomodified montmorillonite) fillers up to 15 wt% on toluene sorption and migration phenomena was studied. As a result, the introduction of fillers, whatever the filler type, led to modification of the extraction profile of the oligomers. However, ZnO and MMT fillers had little effect on toluene sorption compared to graphite. Indeed, a significant decrease in the amount of toluene sorbed by the matrix and a significant slowdown in the toluene diffusion rate were demonstrated for amounts of graphite greater than 10 wt%. Interestingly, a reduction in the migration of low molar mass oligomers was evidenced and attributed to possible adsorption on the filler surfaces. Among the fillers used, graphite-type was more effective, reducing the amount of extracted species by a factor of 3.5. Regarding the impact of fillers on the thermo-oxidative behavior, once again, it was shown that graphite, at concentration higher than 10 wt%, allowed to prevent the antioxidant migration and consequently the thermal-oxidative degradation. Finally, and as expected, another way to improve the thermo-oxidative resistance after immersion in toluene was to increase the initial amount of antioxidants by adding Irganox B225 which is an equimassic mixture of Irganox 1010, a primary antioxidant and Irgafos 168, a secondary antioxidant.

Oligomers in polybutylene terephthalate for food contact—strategies on identification, quantification, and risk assessment

Oligomers are a significant group of migrating substances from food contact materials made of polyesters like polybutylene terephthalate (PBT). Twenty-three cyclic and linear oligomers with different end groups including olefin-terminated oligomers, which are associated with thermal stress of the material, were tentatively identified in PBT extracts by high-performance liquid chromatography with mass spectrometry and diode array detection. Quantification approaches based on chromophore concentration, relative response factors, and overall oligomer determination after hydrolysis to the monomer terephthalic acid were employed. An exhaustive extraction of thirteen PBT samples yielded an overall oligomer content of 1.87–6.10 mg/g material (sum of individual oligomers < 1,000 Da) with a predominant content of cyclic over linear oligomers. Migration experiments were performed according to Regulation (EU) No. 10/2011 using the official food simulants as well as cows’ milk. A total of 218 µg cyclic oligomers/L milk were detected in the third migrate relevant for risk assessment of repeated-use articles under hot-fill conditions (70 °C, 2 h). The official food simulant for milk, 50% ethanol, was found to overestimate the actual migration into milk by a factor of four. Frying conditions using sunflower oil as the food simulant (200 °C, 10 min) resulted in a migration of 7.5 mg cyclic oligomers/kg oil. The exposure to migrating oligomers is critical in some scenarios when evaluated by the threshold of toxicological concern concept; however, the toxicological evaluation poses a challenge due to the possible hydrolysis of cyclic oligomers in the human gastrointestinal tract. Our experiments display the need for a toxicological evaluation of PBT oligomers because the migration of cyclic oligomers is expected to exceed the current in silico–based thresholds under foreseeable conditions of use.

Evaluating the food safety and risk assessment evidence-base of polyethylene terephthalate oligomers: Protocol for a systematic evidence map.

Polyethylene terephthalate (PET) oligomers are ubiquitous in PET used in food contact applications. Consumer exposure by migration of PET oligomers into food and beverages is documented. However, no specific risk assessment framework or guidance for the safety evaluating of PET oligomers exist to date. The aim of this systematic evidence map (SEM) is to identify and organize existing knowledge clusters and associated gaps in hazard and exposure information of PET oligomers. Research needs will be identified as an input for chemical risk assessment, and to support future toxicity testing strategies of PET oligomers and regulatory decision-making. Multiple bibliographic databases (incl. Embase, Medline, Scopus, and Web of Science Core Collection), chemistry databases (SciFinder-n, Reaxys), and gray literature sources will be searched, and the search results will be supplemented by backward and forward citation tracking on eligible records. The search will be based on a single-concept PET oligomer-focused strategy to ensure sensitive and unbiased coverage of all evidence related to hazard and exposure in a data-poor environment. A scoping exercise conducted during planning identified 34 relevant PET oligomers. Eligible work of any study type must include primary research data on at least one relevant PET oligomer with regard to exposure, health, or toxicological outcomes. For indexed scientific literature, title and abstract screening will be performed by one reviewer. Selected studies will be screened in full-text by two independent reviewers. Gray literature will be screened by two independent reviewers for inclusion and exclusion. Risk of bias analysis will not be conducted as part of this SEM. Will be performed by one reviewer and peer-checked by a second reviewer for indexed scientific literature or by two independent reviewers for gray literature. The extracted and coded information will be synthesized in different formats, including narrative synthesis, tables, and heat maps. Zenodo: https://doi.org/10.5281/zenodo.6224302.

Migration and Chemical Characterization of Cyclic Oligomers from Polyester Fiber in Waterless Dyeing System

Migration and Chemical Characterization of Cyclic Oligomers from Polyester Fiber in Waterless Dyeing System

Migration of styrene oligomers from food contact materials: in silico prediction of possible genotoxicity

Styrene oligomers (SO) are well-known side products formed during styrene polymerization. They consist mainly of dimers (SD) and trimers (ST) that have been shown to be still residual in polystyrene (PS) materials. In this study migration of SO from PS into sunflower oil at temperatures between 5 and 70 °C and contact times between 0.5 h and 10 days was investigated. In addition, the contents of SD and ST in the fatty foodstuffs créme fraiche and coffee cream, which are typically enwrapped in PS, were measured and the amounts detected (of up to 0.123 mg/kg food) were compared to literature data. From this comparison, it became evident, that the levels of SO migrating from PS packaging into real food call for a comprehensive risk assessment. As a first step towards this direction, possible genotoxicity has to be addressed. Due to technical and experimental limitations, however, the few existing in vitro tests available are unsuited to provide a clear picture. In order to reduce uncertainty of these in vitro tests, four different knowledge and statistics-based in silico tools were applied to such SO that are known to migrate into food. Except for SD4 all evaluated SD and ST showed no alert for genotoxicity. For SD4, either the predictions were inconclusive or the substance was assigned as being out of the chemical space (out of domain) of the respective in silico tool. Therefore, the absence of genotoxicity of SD4 requires additional experimental proof. Apart from SD4, in silico studies supported the limited in vitro data that indicated the absence of genotoxicity of SO. In conclusion, the overall migration of all SO together into food of up to 50 µg/kg does not raise any health concerns, given the currently available in silico and in vitro data.

Influence of cooking conditions on the migration of silicone oligomers from silicone rubber baking molds to food simulants

The stability, surface micromorphology, and volatile organic compounds (VOCs) of silicone rubber baking molds (SRBMs) were tested while using the molds under severe conditions: baking at 175 °C, microwaving at 800 W, and freezing at −18 °C. Moreover, migration tests of SRBMs to food simulants (isooctane, 95% ethanol, and Tenax®) at 70 °C for 2 h (accelerated conditions) were performed. The initial total VOCs concentration was 2.53% higher than that recommended by BfR Recommendations on Food Contact Materials. Therefore, the SRBM samples were considered as badly tempered materials, and 18 different types of silicone oligomers were identified during the migration tests. The following percentage of silicone oligomers with a molecular weight lower than 1000 Da in isooctane, 95% ethanol, and Tenax® were detected: 70.7%, 91.8%, and 97.2%, respectively. It has been proven that previous baking treatments effectively reduced the content of silicone oligomers migrating from SRBMs.

Migration of Polypropylene Oligomers into Ready-to-Eat Vegetable Soups.

Polyolefin oligomeric hydrocarbons (POH) are non-intentionally added substances (NIAS) which mainly reside in the polymer (PE, PP) as a consequence of the polymerization process, and that under favorable conditions (high fat content, high temperature, and long contact time) may migrate at high amount from the packaging into the food. The food industry offers a wide range of ready-to-eat products, among these, vegetable soups designed to be stored at refrigeration temperature (for times around 6 weeks), and in most cases to be heated for a few minutes in a microwave oven (into the original container, mostly of PP) before consumption. The present work aimed to study for the first-time migration of POH during the shelf life of these products, including storage at refrigeration temperature and after microwave heating. On-line high-performance liquid chromatography (HPLC)-gas chromatography (GC), followed by flame ionization detection (FID), was applied for POH analysis in a number of ready-to-eat products purchased from the Italian market. Microwave heating determined a variable POH increase ranging from 0.1 to 6.2 mg/kg. Parameters possibly affecting migration such as fat content and heating time were also studied.

Influence of medicinal and aromatic plants into risk assessment of a new bioactive packaging based on polylactic acid (PLA)

A new biodegradable antioxidant active packaging for food applications based on antioxidants from medicinal and aromatic plants incorporated into a polylactic acid matrix was designed and developed. Melt blending processing technique was applied to prepare polylactic acid films loaded by sage and lemon balm leaves. Antioxidant properties of developed active films were investigated using the following methods: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl and a home-made generator of hydroxyl radicals. In addition, reducing power and total phenolic content of polylactic acid films were checked. The results of antioxidant capacity showed that percentage of hydroxylation for active film with lemon balm and sage was 55.5% ± 0.1% and 67.4% ± 0.3%, respectively. The reducing power of active films increased 8 times in comparison to the blank samples.Moreover, extensive investigation of influence of sage and lemon balm leaves on material safety and type of migrants was performed using migration assays. The composition of both non-volatile and volatile compounds of different active packaging films was compared with neat polylactic acid film. Three different food simulants such as 95% (v/v) ethanol, 10% (v/v) ethanol and 3% (w/v) acetic acid were checked. It was shown that the addition of sage and lemon balm leaves into a polylactic acid structure decreased the migration of both linear and cyclic polylactic acid oligomers, currently not legislated by European Union. Besides, total absence or decrease of migration of volatile compounds were observed when using the active films. Both thermal and mechanical properties of films were also evaluated.

Migration of oligomers from a food contact biopolymer based on polylactic acid (PLA) and polyester.

Polylactic acid (PLA) is a biopolymer commonly used in food packaging due to its good characteristics, similar to PET. To evaluate the safety of this material, the analysis of the non-intentionally added substances (NIAS) is required. Oligomers are NIAS and their behavior needs a deep study, especially if they migrate to the food. In this work, the analysis of the polymer and the migration to food simulants was carried out. A total dissolution/precipitation procedure was applied to PLA pellets and films, using dichloromethane and ethanol as solvent and antisolvent system respectively. The migration tests were carried out in three liquid simulants to mimic any kind of food. Since oligomers are not present in the positive list of the Directive 10/2011/EC, their concentration must be below the 0.01mg/kg of food. UPLC-QTOF-MS, with and without ion mobility (IM), was used for the analysis. Thirty-nine different PLA oligomers made of repeated monomer units of [LA] (C3H4O2) and with different structures were identified. They corresponded to cyclic oligomers with [LA]n structure and two groups of linear oligomers, one with an hydroxyl group, OH-[LA]n-H, and the other one with an ethoxy group, CH3-CH2-O-[LA]n-H. Cyclic oligomers only appeared in the material and were not present in migration solutions. Linear oligomers HO-[LA]n-H were already present in the pellets/film and they migrated in a higher extension to aqueous food simulants (EtOH 10% and AcH 3%). However, linear oligomers CH3-CH2-O-[LA]n-H were not present initially in the pellets/film, but were detected in migration to simulants with ethanol content, EtOH 95% and EtOH 10%. Furthermore, 5 cyclic polyester oligomers were identified in migration. Ethanol 95% and ethanol 10% migration solutions were also analyzed by scanning electron microscopy (SEM), and the presence of microstructures that could be attributed to the oligomers migration was found. They could be seen as microplastics.

Risk assessment for migration of styrene oligomers into food from polystyrene food containers

Regulation EU 10/2011 requires a risk assessment of Non Intentionally Added Substances (NIAS) migrating into food for food contact plastics within the EU. Styrene oligomers are important potential components of NIAS in polystyrene used for food packaging and so far only dimers and trimers have been identified. They are not genotoxic in vitro, and there is good evidence that they are not endocrine disruptors. Hazard characterization to establish “safe” exposure levels is based on 1. The No Adverse Effect Level (NOAEL) of 1 mg/kg bw/d in an oral rat study during pregnancy and lactation and 2. The concept of Threshold of Toxicological Concern (TTC). Likely human exposure is derived from 1. the concentrations of dimers and trimers in food simulants or 2. in food and 3. the probabilistic FACET exposure estimation based on dimer and trimer concentrations in polystyrene and their potential for migration. The Margin of Safety as the relation of potential consumer exposure and the “safe” exposure level was always above 1 (apart from migration with 95% ethanol which is no longer recommended as an official food simulant for overall migration into fatty food) demonstrating that dimers and trimers in PS food packaging present a low risk for consumers.

Oligomers in polyethylene naphthalate and polybutylene terephthalate – Identification and exploring migration

Polyethylene naphthalate and polybutylene terephthalate were investigated regarding their oligomer content. Based on their accurate mass and fragmentation spectra ten oligomers have been identified in extracts of PBT material and seven oligomers in extracts of PEN material. These oligomers were found to be cyclic and linear for both polymers. They consist of the respective diacid and monoglycol monomers as well as diglycol monomers. The total oligomer content in the polyesters was determined with LC-UV using the cyclic PET trimer as external standard and was found to be 0.81% for PEN and 0.34% for PBT. Migration of PBT oligomers was studied into 20% ethanol (v/v) at 40 °C and 60 °C and the diffusion coefficients thus derived were compared to theoretically determined ones. To estimate the PEN and PBT oligomer migration at 23 °C under long time storage conditions the diffusion coefficients were calculated using the approaches by Welle and Piringer. For cyclic PBT oligomers the Welle model underestimates the migration, for one linear PBT oligomer the Piringer model might be suitable to determine the migration. In the chosen scenario the resulting total oligomer migration was below 30 μg kg−1 for both materials.

SUPERSEDED: Safety assessment of the substance poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) for use in food contact materials.

This opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF Panel) deals with the safety assessment of poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate), Chemical s Service (CAS) No 147398‐31‐0 and food contact material (FCM) substance No 1059, for contact with dry/solid food. This biodegradable (co)polymer is produced by fermentation of palm oil using a genetically modified microorganism (Cupriavidus necator). No migration of oligomers into food simulant E (10 days at 40 and 60°C) was found at a detection limit per single oligomer of 5 μg/kg food. Migration of the degradation product crotonic acid was 8 and 25 μg/kg at the two test temperatures, respectively. The other migrating substances detected, ■■■■■, likely originated from or are related to the authorised substance (FCM No. 9) ‘palm oil and/or palm fatty acid distillate’ used as carbon source for the fermentation. At the migration levels reported, these migrants do not give rise to safety concern. No genotoxicity data are required for poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate) because of its high molecular weight. The fraction below 1,000 Da is 0.5%. The major monomeric unit in the copolymer, 3‐hydroxybutyric acid, is an intermediate in fatty acid metabolism. The minor monomeric unit, 3‐hydroxyhexanoic acid, tested negative for bacterial gene mutations. Degradation products, which may be present in the (co)polymer, are crotonic acid and (E)‐2‐hexenoic acid. Crotonic acid is authorised for use in FCM with a specific migration limit (SML) of 0.05 mg/kg food; for (E)‐2‐hexenoic acid, no indication for genotoxicity was identified by the EFSA CEF Panel in its 2010 group evaluation of flavouring substances in FGE.05Rev2. The CEF Panel concluded that the substance poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate) is not of safety concern if used alone or in blends with other polymers for contact with dry/solid food. If the SML of crotonic acid is met, migration of (E)‐2‐hexenoic acid will also not exceed 0.05 mg/kg food.

The determination of monomers and oligomers from polyester-based can coatings into foodstuffs over extended storage periods

ABSTRACTThe polymeric coating used in metal packaging such as cans for foods and beverages may contain residual amounts of monomers used in the production of the coating, as well as unreacted linear and cyclic oligomers. Traditionally, although designed for use with plastic food contact materials, food simulants have been used to determine the migration of monomers from coatings into foodstuffs. More recently, food simulants have also been used to determine oligomeric species migrating from can coatings. In the work reported here, the migration of both monomers and oligomers from polyester-based can coatings into food simulants and foodstuffs, some of which were towards the end of their shelf-life, is compared. The concentrations of monomers and selected oligomers in canned foods at the end of their shelf life were found to be significantly lower than those in food simulants, which in turn was lower than those in the extraction solvent acetonitrile.

Linear and cyclic oligomers in polybutylene terephthalate for food contact materials

ABSTRACTPolybutylene terephthalate (PBT) is a polyester (PES) gaining more importance on the food contact material (FCM) market. However, little is known about the potential migration of PBT oligomers which are formed during polymer production. In this work, PBT pellets and a slotted spoon manufactured from this material by injection moulding were analysed on extractable oligomers and their migration potential into hydrophilic foods. Overall 27 oligomers (cycles and linears) could be identified in different extracts by HPLC-DAD/ESI-MS data, but without confirmation by reference substances. The oligomers were quantified by HPLC-DAD using bis(2-hydroxyethyl) terephthalate (BHET) as external standard and the total amount of oligomers isolated by reprecipitation from the pellets and the spoon were 0.69 and 0.71%, respectively. While cyclic oligomers made up for approximately 90% of the extractable oligomers, linear oligomers proved to be more relevant for migration into aqueous foodstuffs. Furthermore, it was shown that hydrolysis of oligomers can take place in water at elevated temperatures. Consequently, the qualitative and quantitative composition of PBT oligomers in aqueous foods from FCMs does not only depend on migration but also on hydrolysis. Migration testing of the PBT spoon under repeat use conditions with water at 100°C for 2 h resulted in 0.29 mg item−1 of linear oligomers and 0.05 mg item−1 of the cyclic PBT dimer in the third migrate.

Migration of oligomers from PET: determination of diffusion coefficients and comparison of experimental versus modelled migration

ABSTRACTPolyethylene terephthalate (PET) is increasingly used as food-contact material in, for example, containers for beverage such as bottles for soft drinks, mineral water, juices and beer. Mass transport of substances present in packaging materials into the packed food and beverages is monitored to verify the food law compliance of the materials. PET is known to contain or give rise to migrants that are oligomers derived from the polymeric material. Until now their actual migration potential has been investigated only poorly. A convenient way to determine their migration would be by using models. To verify existing models with experimental data, a migration kinetic study of PET oligomers was conducted. PET bottle material was submerged in 50% ethanol at 80°C for 15 h. The oligomer content in the migration solutions was determined every hour using LC-MS with the first-series cyclic PET trimer as standard. Diffusion coefficients of five PET oligomers (first-series dimer and trimer, second-series dimer and trimer, and third-series dimer) were calculated from the obtained data and compared with the calculated diffusion coefficients using the models of Welle and Piringer. This is the first study to provide diffusion characteristics of oligomers in PET other than the first-series cyclic trimer.

Safety assessment of the substance (butadiene, styrene, methyl methacrylate, butyl acrylate) copolymer cross‐linked with divinylbenzene or 1,3‐butanediol dimethacrylate for use in food contact materials

This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) deals with the safety re-assessment of (butadiene, styrene, methyl methacrylate, butyl acrylate) copolymer cross-linked with divinylbenzene or 1,3-butanediol dimethacrylate for use at up to 40% w/w in blends of styrene acrylonitrile copolymer (SAN)/poly(methyl methacrylate) (PMMA). Finished articles are intended for repeated contact at room temperature or below with aqueous, acidic and/or low alcoholic foodstuffs for less than 1 day and with dry foodstuffs for more than 1 day. The substance has a low molecular weight fraction (LMWF) below 1,000 Da up to 3.3%. It starts to thermally degrade at ca 230°C, below the maximum temperature of processing finished articles, 250°C. Among the substances released from the heated polymeric additive, four were detected to be released from the finished food contact material (FCM). Migration of oligomers and reaction products into 3% acetic acid and 20% ethanol from a SAN/PMMA material was found to decrease with repeated uses. After the third contact, cyclo-octatetraene, toluene and a hexanedioic acid related substance were detected by GC–MS analysis of the simulant samples, at approximately 5 μg/kg food. From analysis with headspace-GC–MS of heated plastic samples with and without the substance, four volatiles were (semi)quantified at ca 1 μg/6 dm2 or less. Considering that the substance is a polymeric additive without structural alert for genotoxicity, manufactured using authorised monomers and with limited potential migration of the LMWF, no toxicological data were requested. The CEF Panel concluded that the substance is not of safety concern for the consumer if it is used at up to 40% w/w in blends of SAN/PMMA repeat-use articles intended for contact at room temperature with aqueous, acidic and/or low alcoholic foodstuffs for less than 1 day and with dry foodstuffs without a time limit.

Migration of Cyclic Monomer and Oligomers from Polyamide 6 and 66 Food Contact Materials into Food and Food Simulants: Direct Food Contact

Cyclic monomer and oligomers are the major migrating substances from polyamide (PA) food contact materials. An increase of caprolactam (+44%) and cyclic oligomer content (+27%, incl. caprolactam) in PA6 was observed by thermal treatment, here by extrusion of a PA6 film from a granulate. Migration experiments with a PA6 and a PA66 packaging film were carried out into food simulants according to directives 85/572/EEC and 82/711/EEC. Contact conditions (2 h/100°C) were chosen for a heat treatment of the food in the packaging, in this case production of scalded sausage. Aqueous and ethanolic food simulants clearly revealed to be the worst case for migration of cyclic PA6 and PA66 monomer and oligomers. Migration of cyclic oligomers into oil was one order of magnitude lower. No migration could be observed into isooctane (<8 µg dm−2). The substitutes for oil, 95% ethanol and isooctane, were inapplicable for simulating migration of cyclic oligomers into oil. Caprolactam showed different migration behaviour compared with cyclic oligomers, migrating into oil and water to the same extent depending on contact conditions. Fifty percent of the extractable caprolactam migrated from a PA6 sausage casing into scalded sausage (4.2 mg kg−1), residual 41% apparently were extracted by the boiling medium or during pretreatment (soaking) of the casing. Potential migration of caprolactam and cyclic oligomers from a PA6 tea bag was found to be 18% of the specific migration limit for caprolactam and 36% of the overall migration limit. Copyright © 2014 John Wiley & Sons, Ltd.