Perfluorochemicals: Potential sources of and migration from food packaging

Perfluorochemicals are widely used in the manufacturing and processing of a vast array of consumer goods, including electrical wiring, clothing, household and automotive products. Furthermore, relatively small quantities of perfluorochemicals are also used in the manufacturing of food-contact substances that represent potential sources of oral exposure to these chemicals. The most recognizable products to consumers are the uses of perfluorochemicals in non-stick coatings (polytetrafluoroethylene (PTFE)) for cookware and also their use in paper coatings for oil and moisture resistance. Recent epidemiology studies have demonstrated the presence of two particular perfluorochemicals, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in human serum at very low part per billion levels. These perfluorochemicals are biopersistent and are the subject of numerous studies investigating the many possible sources of human exposure. Among the various uses of these two chemicals, PFOS is a residual impurity in some paper coatings used for food contact and PFOA is a processing aid in the manufacture of PTFE used for many purposes including non-stick cookware. Little information is available on the types of perfluorochemicals that have the potential to migrate from perfluoro coatings into food. One obstacle to studying migration is the difficulty in measuring perfluorochemicals by routine conventional analytical techniques such as GC/MS or LC-UV. Many perfluorochemicals used in food-contact substances are not detectable by these conventional methods. As liquid chromatography-mass spectrometry (LC/MS) develops into a routine analytical technique, potential migrants from perfluoro coatings can be more easily characterized. In this paper, data will be presented on the types of perfluoro chemicals that are used in food packaging and cookware. Additionally, research will be presented on the migration or potential for migration of these chemicals into foods or food simulating liquids. Results from migration tests show mg kg^-1 amounts of perfluoro paper additives/coatings transfer to food oil. Analysis of PTFE cookware shows residual amounts of PFOA in the low µg kg^-1 range. PFOA is present in microwave popcorn bag paper at amounts as high as 300 µg kg^-1.     

Investigation into the migration potential of coating materials from cookware products

Twenty-six non-stick-coated cookware samples were purchased, covering a variety of products, coating/metal types and food contact applications. The polymer coatings were identified to be polyethersulphone, polytetrafluoroethylene (PTFE), bisphenol A/epichlorohydrin and one coating for which no good match was obtained with infra-red library spectra. All of the products intended for stove-top use had a polymer coating containing PTFE. The coatings were analysed as purchased and after heating at 250°C for 30 min to simulate actual conditions of use. Total solvent extractables were measured and the overall migration was determined into simulants. None of the products exceeded an overall migration limit of 10 mg dm^-2. Coating materials were analysed by headspace gas chromatography-mass spectrometry (GC-MS), by liquid extraction followed by GC-MS and by liquid extraction followed by liquid chromatography-mass spectroscopy with a particle-beam interface. Benzene was detected in two samples, at 1.4 and 2.4 µg dm^-2. These levels in the coatings are too low to give any detectable migration into foods. There was no detectable release of perfluorochemicals. Several other substances were identified and the worst-case migration was calculated. The origin of many of the substances detected was considered to be by pick-up from the printed packaging materials in which the cookware was sold. Potential consumer exposure was calculated. None of the substances identified had the potential to exceed their tolerable daily intake (TDI) value. To confirm these worst-case calculations, the migration of certain phthalates and of bisphenol A was measured into food simulants. Migration levels were very low.     

Migration from can coatings: Part 3. Synthesis, identification and quantification of migrating epoxy-based substances below 1000 Da

Bisphenol A-derived glycidyl ethers as well as its reaction products with other lacquer components can migrate into the packed food from epoxy-based can coatings. A sensitive and selective method is presented using high-performance liquid chromatography coupled with ultraviolet light, fluorescence and electrospray ionization-mass selective detection for the identification and quantification of all migrants with a bisphenol A backbone and a molecular weight below 1000 Da, an estimated boundary for the absorption in the gastrointestinal tract. The identification of migrants was confirmed by microreactions of technical bisphenol A diglycidyl ether with solvents and phenols, which provided the fragmentation pattern of the mass selective detection and relative retentions of 42 different bisphenol A-related substances. It was shown by calibration of different isolated and synthesized bisphenol A derivatives that the fluorescence response relies on the amount of bisphenol A moiety in the respective molecule. Therefore, all migrating bisphenol A-related substances below 1000 Da were determined as bisphenol A diglycidyl ether equivalents using a calibration (fluorescence detection) of the commercially available bisphenol A diglycidyl ether monomer. The limit of quantification was set at 5 μg bisphenol A diglycidyl ether equivalents kg^-1 (or 0.8 μg dm^-2). This method was validated for epoxy coatings (0.1 μg dm^-2 limit of detection and 24 μg bisphenol A-related substances below 1000 Da dm^-2 standard deviation, corresponding to 4.4% relative standard deviation). The quantification could be extended by combining the fluorescence response and structural information gained from the mass spectra, which provides more accurate results for each migrant. The calculation is based on the calibration of the bisphenol A chromophore content of the molecule. According to this method, the amount of migrating bisphenol A-related substances below 1000 Da in the acetonitrile extract (assuming a worst case) varied from about 0.4 to 0.7 mg dm^-2 in the examined coatings. The determined amounts comply with about 50% of the total migrate below 1000 Da.     

Endocrine modulating chemicals in food packaging: A review of phthalates and bisphenols

Phthalates and bisphenol chemicals have been widely used globally in packaging materials and consumer products for several decades. These highly functional chemicals have become a concern due to their toxicity (i.e., endocrine/hormone modulators) and ability to migrate from food contact materials (FCMs) into food matrices and the environment resulting in human and environmental health risks. FCMs, composed of postconsumer materials, are particularly high risk for containing these compounds. The evaluation of postconsumer recycled feedstocks in FCMs is compulsory and selection of an appropriate detection method to comply with applicable regulations is necessary to evaluate human and environmental safety. Numerous regulations have been proposed and passed globally for both compound classes that are recognized as priority pollutants by the United States Environmental Protection Agency and the European Union. Several brand owners and retailers have also released their own “restricted substance lists” due to the mounting consumer and regulatory concerns. This review article has two goals: (1) discuss the utilization, toxicology, human exposure routes, and occurrence levels of phthalates and bisphenols in FCMs and associated legislation in various countries and (2) discuss critical understanding and updates for detection/quantification techniques. Current techniques discussed include extraction and sample preparation methods (solid-phase microextraction [SPME], headspace SPME, Soxhlet procedure, ultrasound-assisted extraction), chromatographic techniques (gas, liquid, detectors), and environmental/blank considerations for quantification. This review complements a previous review of phthalates in foods from 2009 by discussing phthalate and bisphenol characteristics, analytical methods of determining concentrations in packaging materials, and their influence on the migration potential into food.     

Migration Phenomenon in Food Packaging. Food–Package Interactions, Mechanisms, Types of Migrants, Testing and Relative Legislation—A Review

The development of convenient and low-cost packages, together with the increased consumer demands for safer products, have resulted in the conduction of extensive research and the publication of numerous studies related to the phenomenon of migration. The large number of synthetic materials used for the manufacture of packages makes the evaluation of the food–package interactions quite complicated. Different parameters such as the nature of the food of interest, the type of food–package contact, the time and temperature of contact, the packaging materials used, the properties of the migrating substances, as well as the amount of potential migrants contained in the packaging materials, can drastically affect the migration rate and extent. Due to the extreme variety of foods used, several food simulants have been suggested and applied for testing the migration phenomenon under various laboratory conditions. The use of many of those simulants is defined by national and international legislation. This review article covers the main migration phenomena, which are related to the most commonly used packaging materials. It is clearly demonstrated that the complexity of the migration phenomena requires more research to establish internationally accepted risk management procedures and standardised testing methods.     

Determination of bisphenol A diglycidyl ether (BADGE) and its derivatives in food: identification and quantification by internal standard

Bisphenol A diglycidyl ether (BADGE) and its reaction products with water and hydrochloric acid have recently been subject to new regulations concerning their migration from food packaging into foodstuff. A method for the simultaneous identification and quantification of these substances and their precursor bisphenol A in food is described introducing bisphenol A di-(3-hydroxypropyl)ether as an internal standard. Analysis was carried out using RP-HPLC gradient elution with fluorescence detection. Additional information in the case of suspect samples was obtained using RP-HPLC with mass selective detection. The described method is validated for the analysis of foodstuffs as well as fatty food simulants. The limits of detection were between 10 and 30 µg/kg of food; recovery experiments gave identical behaviour for all analytes and the internal standard. The enforcement of the specific migration limit set by regulatory standards of the European Union for BADGE and its hydrolysis and hydrochlorination products is possible for producers as well as food quality surveillance institutions.     

食品接触材料中挥发性气味物质分析技术的研究进展

目前食品接触材料安全性日益受到关注。食品接触材料产生的挥发性物质,常常具有异常的气味,可能通过气相传质或直接接触迁移至食品中,不但会引发食品感官特性的变化,影响消费者的使用体验,削弱消费者购买欲望,过量摄入后还会危及人体健康。因此,准确识别和检测食品接触材料产生的异味物质,对确保食品接触材料的合规以及保护消费者健康安全显得尤为重要。本文对国内外关于挥发性物质气味评估和检测技术及其在食品接触材料领域的运用进行综述。重点介绍了顶空、顶空-固相微萃取、热脱附、电子鼻等气味分析技术,及其与气相色谱、气相色谱/质谱或气相色谱-嗅闻-质谱仪等结合的联用分析技术,并梳理和展望了食品接触材料中挥发性气味物质分析技术发展前景,为有效管控食品接触材料异味问题提供技术参考。     

Non-targeted multi-component analytical surveillance of plastic food contact materials: Identification of substances not included in EU positive lists and their risk assessment

A procedure used by the Norwegian Food Safety Authority for surveillance of contaminants from plastic food contact materials (polyolefin drinking bottles, water boilers, polyamide cooking utensils and plastic multi-layer materials) is described. It is based on gas chromatographic-mass spectrometric (GC/MS) analysis of food simulants exposed to plastic materials. Most migrants were substances not-intentionally added to the plastic (degradation products, impurities) or originated from non-plastic components, such as printing inks, adhesives, not-listed additives, solvents and coatings. Hence, the majority of the identified migrants were regulated by the general statements in the EU Framework Regulation, which neither specify limits nor requirements regarding risk assessment, rather than by specific migration controls. Risk assessment has been carried out for selected non-authorized substances. The analysis and the management of these substances and materials with respect to safety represents a challenge to the food authorities.     

食品接触塑料材料及制品中高关注化合物的高分辨质谱分析技术研究进展

食品接触塑料材料及制品向食品可能发生的高关注化合物迁移一直是食品接触材料安全研究和合规管理的重点。这些高关注化合物分为有意添加物和非有意添加物。由于塑料食品接触材料高关注化合物来源复杂,迁移水平低且相当数量是未知的物质,在缺乏完整的化学物结构数据库、质谱谱图数据库以及标准品等情况下,对这些物质的鉴定和定量测定一直是食品接触材料安全分析所面临的重大技术挑战。近年来,基于气相色谱、液相色谱与各种高分辨率质谱联用的分析技术被视为一种有效手段,逐渐应用于对食品接触材料中高关注化合物的鉴定和定量分析。本文重点介绍近年来针对食品接触塑料高关注化合物分析的高分辨精确质谱(high resolution mass spectrometry, HRMS)分析技术进展,包括迁移试验条件、前处理技术、数据采集以及数据处理技术等。并总结应用HRMS技术所分析的不同食品接触塑料中的高关注化合物,以期为食品接触塑料的风险评估和管理工作提供参考。     

Correlation of foodstuffs with ethanol–water mixtures with regard to the solubility of migrants from food contact materials

Today most foods are available in a packed form. During storage, the migration of chemical substances from food packaging materials into food may occur and may therefore be a potential source of consumer exposure. To protect the consumer, standard migration tests are laid down in Regulation (EU) No. 10/2011. When using those migration tests and applying additional conservative conventions, estimated exposure is linked with large uncertainties including a certain margin of safety. Thus the research project FACET was initiated within the 7th Framework Programme of the European Commission with the aim of developing a probabilistic migration modelling framework which allows one (1) to calculate migration into foods under real conditions of use; and (2) to deliver realistic concentration estimates for consumer exposure modelling for complex packaging materials (including multi-material multilayer structures). The aim was to carry out within the framework of the FACET project a comprehensive systematic study on the solubility behaviour of foodstuffs for potentially migrating organic chemicals. Therefore a rapid and convenient method was established to obtain partition coefficients between polymer and food, K_P/F. With this method approximately 700 time-dependent kinetic experiments from spiked polyethylene films were performed using model migrants, foods and ethanol–water mixtures. The partition coefficients of migrants between polymer and food (K_P/F) were compared with those obtained using ethanol–water mixtures (K_P/F’s) to investigate whether an allocation of food groups with common migration behaviour to certain ethanol–water mixtures could be made. These studies have confirmed that the solubility of a migrant is mainly dependent on the fat content in the food and on the ethanol concentration of ethanol–water mixtures. Therefore dissolution properties of generic food groups for migrants can be assigned to those of ethanol–water mixtures. All foodstuffs (including dry foods) when allocated to FACET model food group codes can be classified into a reduced number of food categories each represented by a corresponding ethanol–water equivalency.     

Assessment of infant exposure to food chemicals: the French Total Diet Study design

As part of the previous French Total Diet Studies (TDS) focusing on exposure to food chemicals in the population aged 3 years and older, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) launched a specific TDS on infants to complete its overall chemical food safety programme for the general population. More than 500 chemical substances were analysed in food products consumed by children under 3 years old, including nutrients, several endocrine disruptors resulting from human activities (polychlorinated biphenyls, dioxins and furans, brominated flame retardants, perfluoroalkyl acids, pesticide residues, etc.) or migrating from food contact materials such as bisphenol A or phthalates, but also natural substances such as mycotoxins, phytoestrogens and steroids. To obtain a representative and general view of infant food consumption, food items were selected based on results of a national consumption survey conducted specifically on this population. Moreover, a specific study on food was conducted on 429 households to determine which home-cooking practices are employed to prepare food consumed by infants. Overall, the targeted chemical substances were analysed in more than 450 food samples, representing the purchase and home-cooking practices of over 5500 food products. Foods included common foods such as vegetables, fruit or cakes as well as specific infant foods such as infant formula or jarred baby food. The sampling plan covered over 80% of the total diet. Specificities in infant food consumption and habits were therefore considered to define this first infant TDS. This study, conducted on a large scale and focusing on a particularly sensitive population, will provide accurate information on the dietary exposure of children under 3 years to food chemicals, especially endocrine disruptors, and will be particularly useful for risk assessment analysis under the remit of ANSES’ expert committees.     

LC-MS/MS analysis of bisphenol S and five other bisphenols in total diet food samples

ABSTRACT

It is already known that bisphenol S (BPS) has been used as a substitute for BPA in thermal papers in recent years. It is not clear, however, if BPS has also been used to replace BPA in can coatings as currently being speculated due to a lack of credible studies on migration of BPS from can coatings and occurrence data of BPS in foods. In this study, an LC-MS/MS method was developed for the analysis of BPS, along with several other bisphenols, and method detection limits for BPS varied from 0.0017 to 3.1 ng/g depending on the type of sample matrix and the amount of sample analysed. This method was used to analyse 159 different food composite samples from a recent Canadian total diet study. Bisphenol E (BPE), bisphenol B (BPB), and bisphenol AF (BPAF) were not detected in any of the 159 food composite samples, bisphenol F (BPF) was detected in only three samples (25–2360 ng/g), and bisphenol A (BPA) was detected in 10 samples (5.3–41 ng/g) which were all prepared from canned foods. BPS was not detected in any of the canned food composite samples but was detected in nine food composite samples prepared from meat and meat products (1.2–35 ng/g), indicating sources for BPS other than can coatings may be possible, which will be investigated in future studies.     

Presentation and comments on EU legislation related to food industries–environment interactions: organic contaminants (chemicals, pesticides, dioxins, furans, biocides and their waste management)

The first part of this review on European Union (EU) legislation related to food industries–environment interactions deals with chemicals which, in their majority, make their way to food. Such substances are the pesticides and fertilizers the residues of which abound in many agricultural produces (both of plant or animal origin). Another crucial issue is the unintentional release of dioxins and furans through combustion. Detergents or sanitizers in conjunction with compounds considered hazardous or corrosive or flammable stand for other topics falling in the general category of chemicals employed in the food industry. The aim of this review is to cover all the current EU legislation in the field of chemicals (dioxins, furans, pesticides, biocides products, fertilizers, sanitizers) coming directly or indirectly in contact with food and their waste management by providing six comprehensive and easy‐to‐use tables, and a synopsis of the main points of the currently in force EU legislation.     

Development of a new modelling tool (FACET) to assess exposure to chemical migrants from food packaging

The approach used to obtain European Union-wide data on the usage and concentration of substances in different food packaging materials is described. Statistics were collected on pack sizes and market shares for the different materials used to package different food groups. The packaging materials covered were plastics (both flexible and rigid), metal containers, light metal packaging, paper and board, as well as the adhesives and inks used on them. An explanation as to how these data are linked in various ways in the FACET exposure modelling tool is given as well as an overview of the software along with examples of the intermediate tables of data. The example of bisphenol A (BPA), used in resins that may be incorporated into some coatings for canned foodstuffs, is used to illustrate how the data in FACET are combined to produce concentration distributions. Such concentration distributions are then linked probabilistically to the amounts of each food item consumed, as recorded in national food consumption survey diaries, in order to estimate exposure to packaging migrants. Estimates of exposure are at the level of the individual consumer and thus can be expressed for various percentiles of different populations and subpopulations covered by the national dietary surveys.     

Establishment of a reference collection of additives and an analytical handbook of reference data to support enforcement of EU regulations on food contact plastics.

A collection has been made of additives that are required as analytical standards for enforcement of European Union legislation on food contact plastics. The 100 additives have been characterized by mass spectrometry, infra-red spectroscopy and proton nuclear magnetic resonance spectroscopy to provide reference spectra. Gas chromatographic retention times have been recorded to facilitate identification by retention index. This information has been further supplemented by physico-chemical data. Finally, chromatographic methods have been used to indicate the presence of any impurities in the commercial chemicals. Samples of the reference substances are available on request and the collection of spectra and other information will be made available in printed format and on-line through the Internet. This paper gives an overview of the work done to establish the reference collection and the spectral atlas, which together will assist enforcement laboratories in the characterization of plastics and the selection of analytical methods for additives that may migrate.     

食品和药品接触材料聚丙烯中添加剂及 物质迁移的液相色谱分析

聚丙烯(PP)塑料被广泛用在食品及药品的包装上,PP中有害物质的迁移现已成为食品及药品安全隐患的重要组成部分,当食品与包装材料直接接触时,残留在PP包装材料里的抗氧剂及分解产物可以迁移到食品中污染食品。由于食品的多样性,因此常用几种食品模拟液来代替食品在实验室各种控制条件下进行迁移试验,因为迁移到模拟液里的添加剂浓度非常小,其浓度的测定常使用灵敏度较高的高效液相色谱法。迁移受到很多因素的影响,比如:接触的时间温度、接触的方式、包装材料的类型、迁移物的性质等。本文综述了聚丙烯包装材料有害物质迁移的研究现状,为我国食品包装行业标准化体系的建立提供一定的理论依据。     

食品接触用再生PET制品中非有意/有意添加物迁移量的筛查及安全评估

为评估再生PET材料中非有意/有意添加物的迁移风险,采用液相四极杆飞行时间质谱、气相色谱串联质谱和顶空串联气相色谱法建立了再生PET制品中非有意/有意添加物筛查的方法,并对迁移实验所得食品模拟物进行检测。结果表明,共筛查出了6个化合物,其中油酸甲酯、棕榈酸甲酯、三甘醇辛酸癸酸酯和三乙二醇二异辛酸酯等4个化合物是有意添加物,亚油酸甲酯和1, 2-双-（4-羧基-苯甲酰基）-乙烷是非有意添加物。检出的化合物均未在GB 9685-2016食品安全国家标准中列出,是未被允许使用的化学物质。依据毒理学关注阈值法评估所检出的化合物均为Cramer Ⅰ类物质,结合膳食暴露条件评估它们的暴露量大大低于安全暴露阈值1.8 mg/人/d,对人体健康产生危害的可能性较低。     

Assessing the safety of co-exposure to food packaging migrants in food and water using the maximum cumulative ratio and an established decision tree

Food contact materials can release low levels of multiple chemicals (migrants) into foods and beverages, to which individuals can be exposed through food consumption. This paper investigates the potential for non-carcinogenic effects from exposure to multiple migrants using the Cefic Mixtures Ad hoc Team (MIAT) decision tree. The purpose of the assessment is to demonstrate how the decision tree can be applied to concurrent exposures to multiple migrants using either hazard or structural data on the specific components, i.e. based on the acceptable daily intake (ADI) or the threshold of toxicological concern. The tree was used to assess risks from co-exposure to migrants reported in a study on non-intentionally added substances (NIAS) eluting from food contact-grade plastic and two studies of water bottles: one on organic compounds and the other on ionic forms of various elements. The MIAT decision tree assigns co-exposures to different risk management groups (I, II, IIIA and IIIB) based on the hazard index, and the maximum cumulative ratio (MCR). The predicted co-exposures for all examples fell into Group II (low toxicological concern) and had MCR values of 1.3 and 2.4 (indicating that one or two components drove the majority of the mixture’s toxicity). MCR values from the study of inorganic ions (126 mixtures) ranged from 1.1 to 3.8 for glass and from 1.1 to 5.0 for plastic containers. The MCR values indicated that a single compound drove toxicity in 58% of the mixtures. MCR values also declined with increases in the hazard index for the screening assessments of exposure (suggesting fewer substances contributed as risk potential increased). Overall, it can be concluded that the data on co-exposure to migrants evaluated in these case studies are of low toxicological concern and the safety assessment approach described in this paper was shown to be a helpful screening tool.     

12种婴幼儿食品接触热塑性弹性体制品中潜在迁移物的分析

利用固相微萃取-气相色谱-质谱联用技术对12种婴幼儿食品接触热塑性弹性体制品中挥发性及半挥发性的潜在迁移物进行定性及半定量分析。样品通过DVB/CAR/PDMS、CAR/PDMS、Polyacrylate三个固相微萃取纤维头进行非目标物的提取,气相色谱-质谱联用进行分离鉴定,检出的68种化合物结合标准品和保留指数进行确证,单点内标法进行半定量分析。根据检出率、保留指数及含量进行步分3级筛选,最后提出32种需要重点关注的化合物,包括硅氧烷类、芳香烃类、烷烃类、醛类、酯类及酚类等。该研究为后续的特定物质的迁移实验、暴露评估等研究提供了研究思路和科学依据。     

农药残留检测实验室标准物质的管理

实验室的农药残留检测用标准物质对实验室农产品的农药残留检测工作具有重大的意义。农药残留检测用标准物质大部分为剧毒化学品,管理不当有可能会引发公共安全事故,所以建立健全剧毒化学品管理制度,加强宣贯培训,才能有效地指导实验室使用人员规范使用剧毒化学品,确保农药残留检测用标准物质的规范管理,保证安全生产和实验室检验检测工作的顺利进行。本文主要阐述了农药残留实验室的标准物质从采购、验收与入库、储存、领用、期间核查、废弃处置等环节的管理要点,以及国家对剧毒化学品管理的相关规定,以通过标准物质的规范化、法制化、科学化管理,来保证农药残留标准物质的正确使用、质量控制与溯源,确保实验室标准物质的安全管理。