Migration from food contact plastics. Part I. Establishment and aims of the PIRA project

In the European Community regulatory approaches adopted by individual Member States to the control of food contact plastics differ markedly and, as a result, the European Commission has identified a need for harmonized legislation in this sector. The Commission requested its Scientific Committee for Food to advise on the toxicity of monomers and other starting substances used in the production of such plastics and the Committee's report has recently been published. It is apparent that, although some monomers have been studied in depth, for many little or no information was available to the Committee on either the levels migrating into food or their likely toxic effects. The Committee has requested that such information be provided within 3 years. Following discussions between the UK Ministry of Agriculture, Fisheries and Food, PIRA and companies involved in either the manufacture or use of food contact plastics, a Project has been established at PIRA to develop sensitive analytical procedures for the relevant UK-required monomers and to provide the required migration data. As a second part to this project the methodology for determining overall migration is being examined with a view to resolving existing experimental difficulties. The first analytical methods to be developed in the project are those for the determination or terephthalic acid and isophthalic acid. Residual levels of these monomers in plastics and the quantities migrating into food simulants and food have been shown to be very low.     

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.     

塑料食品包装材料中有毒有害化学残留物及分析方法

食品包装材料中有毒有害化学物质的迁移是引起食品污染的重要途径之一。本文主要根据近年来发表的有关食品包装材料、卫生检测领域的相关文献为基础,针对塑料食品包装材料中的单体、低聚体、添加剂和污染物等几类有毒有害化学物质的组成、毒性、卫生限量标准及主要检测方法进行了分析,为相关食品包装企业的质量控制技术人员和科研工作者提供参考。     

Use of overall migration methodology to test for food-contact substances with specific migration limits

This work investigated if overall migration test procedures could also be used to test for the migration of specific substances from plastics. The overall migration test procedure used was the evaporative gravimetric method used with volatile food simulants. Thirty food-contact substances (additives and monomers) were tested for their chemical stability and volatile loss during the heated evaporation stage of the overall migration procedure. Eighteen of the 30 were determined in an acceptable yield. It is concluded that in the list of approximately 620 European Union substances that have specific migration limits of 5 mg kg^?1 or higher, and based on considerations of stability and volatility, more than half could be amenable to control using overall migration methodology. This is particularly the case for inert plastics with low intrinsic overall migration values of oligomers. This means that based on the overall migration test result found, testing laboratories could decide on a case-by-case basis if known additives and starting substances are covered by the overall migration result and no separate testing would be required for specific migration, with time and resource cost savings.     

Chromatographic Methods for the Determination of Polyfunctional Amines and Related Compounds Used as Monomers and Additives in Food Packaging Materials: A State‐of‐the‐Art Review

Abstract: Polyfunctional amines are a group of substances commonly used as additives or monomers in food‐contact materials. These substances can migrate into foodstuffs and, consequently, may be potentially dangerous for human health. Due to their different chemical structures and physicochemical properties there does not exist a standard method to analyze polyfunctional amines. This review aims to provide an update on the chromatographic methods used for the determination of polyfunctional amines that are commonly used in the manufacture of food packaging materials. Detailed information regarding chromatographic conditions (mobile phases, chromatographic columns, detection systems, and so on) is provided. Moreover, chemical structures and physicochemical properties of the substances studied are also presented.     

Kinetic migration studies from packaging films into meat products

One of the main concerns regarding safety of food packaging is the possible migration of chemical substances (monomers and other starting substances, additives, residues) from food contact materials into foods. To evaluate the effect of the fat content and of the temperature of storage on the migration from plastics packaging films into meat products as an important class of foodstuffs, the kinetic mass transport of a model migrant (diphenylbutadiene) from low density polyethylene (LDPE) film in contact with different meat products was investigated. From the data, the diffusion coefficients were calculated for the applied test conditions, by use of a mathematical model. The results showed that migration increased with fat content and storage temperature. Analysis of migration data corresponding to minced pork meat containing different amounts of fat, stored for 10 days at 25°C, revealed an excellent relationship between migration level and fat content. This behaviour was also found for other types of meat products (chicken and pork neck). A simplifying mathematical model was applied to derive effective diffusion coefficients in the polymer which, however, do take kinetic effects in the meat also into account. In the case of pork meat contact, the effective diffusion coefficients derived from mathematical modelling were ten times higher for storage at 25°C (1.88×10(-9)cm(2)s(-1)) than for storage at 5°C (1.2×10(-10)cm(2)s(-1)).     

Estimation of exposure to food packaging materials. 1: Development of a food-packaging database

A food-packaging database was developed to provide qualitative information on the types of packaging materials used for foods. Packaging information was collected from a sample of 594 children aged 5-12 years as part of a national children's food survey carried out in Ireland during 2003-04. All the food packaging collected during the survey was forwarded to the coordinating centre for further analysis and entry into the Irish Food Packaging Database. The database was created in Microsoft Access® and stored information on: the brand of the food, the packaging type, the unit weight, the contact layer, the European Union food type (i.e. aqueous, acidic, alcoholic or fatty) and other relevant parameters. Of the 5551 different brand foods consumed by children in the food survey, packaging information was collected on 3441 (62%). As some brand foods had different unit weights and packaging formats, there was duplication of some brand foods in the database to account for this fact. Therefore, there were 3672 packaging entries in the database. Of these, plastics were the most common packaging contact layer (n = 2874, 78.3%). Multimaterial multilayers with a plastic contact layer accounted for 459 (12.5%) entries. Polyethylene was the most frequently used contact layer (n = 941), with polypropylene a close second (n = 809). This database is unique in Europe for the quality and amount of food packaging information it contains and could be used to develop packaging use factors for a more refined exposure assessment to food packaging materials in the European Union.     

食品接触塑料中化学成分迁移研究方法进展

塑料以其优良的物理化学性能和低廉的价格广泛应用于食品接触制品中。然而食品长期与塑料包装接触可能导致塑料中化学成分向食品中迁移,进而造成食品污染,并最终危害消费者的身体健康。故食品接触塑料中化学成分的迁移行为受到国内外政府机构和科研工作者的广泛关注。本文简述了食品接触塑料迁移实验中食品模拟物的选择、迁移实验条件的设定,以及受限物质的检测方法。并对食品接触塑料中的光引发剂、重金属元素、增塑剂等三类化学成分的迁移规律的研究进行综述。     

我国食品接触材料安全性评估体系构建

食品接触材料中所有可能迁移到食品中的物质均需要评估,包括单体、起始物和添加剂等有意添加物,以及杂质、生产过程中产生的副反应产物和降解物等非有意添加物。食品接触材料的安全性评估主要分为上市前的安全性评估和上市后的监测评估。目前,国际上食品接触材料上市前的安全性评估主要有美国和欧盟两种评估模式,两种方法各有优缺点。我国目前尚未建立食品接触材料上市前安全性评估的基本参数。构建我国食品接触材料安全性评估体系是国家食品安全风险评估专家委员会确定的"十三五"期间的重点工作。本文介绍了我国食品接触材料安全性评估体系的构成、预期目标以及食品接触材料风险评估面临的挑战。     

A critical review on biodegradable food packaging for meat: Materials,sustainability, regulations,and perspectives in the EU

The development of biodegradable packaging is a challenge, as conventional plastics have many advantages in terms of high flexibility, transparency, low cost, strong mechanical characteristics, and high resistance to heat compared with most biodegradable plastics. The quality of biodegradable materials and the research needed for their improvement for meat packaging were critically evaluated in this study. In terms of sustainability, biodegradable packagings are more sustainable than conventional plastics; however, most of them contain unsustainable chemical additives. Cellulose showed a high potential for meat preservation due to high moisture control. Polyhydroxyalkanoates and polylactic acid (PLA) are renewable materials that have been recently introduced to the market, but their application in meat products is still limited. To be classified as an edible film, the mechanical properties and acceptable control over gas and moisture exchange need to be improved. PLA and cellulose-based films possess the advantage of protection against oxygen and water permeation; however, the addition of functional substances plays an important role in their effects on the foods. Furthermore, the use of packaging materials is increasing due to consumer demand for natural high-quality food packaging that serves functions such as extended shelf-life and contamination protection. To support the importance moving toward biodegradable packaging for meat, this review presented novel perspectives regarding ecological impacts, commercial status, and consumer perspectives. Those aspects are then evaluated with the specific consideration of regulations and perspective in the European Union (EU) for employing renewable and ecological meat packaging materials. This review also helps to highlight the situation regarding biodegradable food packaging for meat in the EU specifically.     

Optimisation of an analytical method and results from the inter-laboratory comparison of the migration of regulated substances from food packaging into the new mandatory European Union simulant for dry foodstuffs

This paper presents the outcome of the development, optimisation and validation at European Union level of an analytical method for using poly(2,6-diphenyl phenylene oxide – PPPO), which is stipulated in Regulation (EU) No. 10/2011, as food simulant E for testing specific migration from plastics into dry foodstuffs. Two methods for fortifying respectively PPPO and a low-density polyethylene (LDPE) film with surrogate substances that are relevant to food contact were developed. A protocol for cleaning the PPPO and an efficient analytical method were developed for the quantification of butylhydroxytoluene (BHT), benzophenone (BP), diisobutylphthalate (DiBP), bis(2-ethylhexyl) adipate (DEHA) and 1,2-cyclohexanedicarboxylic acid, diisononyl ester (DINCH) from PPPO. A protocol for a migration test from plastics using small migration cells was also developed. The method was validated by an inter-laboratory comparison (ILC) with 16 national reference laboratories for food contact materials in the European Union. This allowed for the first time data to be obtained on the precision and laboratory performance of both migration and quantification. The results showed that the validation ILC was successful even when taking into account the complexity of the exercise. The results showed that the method performance was 7–9% repeatability standard deviation (rSD) for most substances (regardless of concentration), with 12% rSD for the high level of BHT and for DiBP at very low levels. The reproducibility standard deviation results for the 16 European Union laboratories were in the range of 20–30% for the quantification from PPPO (for the three levels of concentrations of the five substances) and 15–40% from migration experiments from the fortified plastic at 60°C for 10 days and subsequent quantification. Considering the lack of data previously available in the literature, this work has demonstrated that the validation of a method is possible both for migration from a film and for quantification into a corresponding simulant for specific migration.     

Comprehensive European dietary exposure model (CEDEM) for food additives

European methods for assessing dietary exposures to nutrients, additives and other substances in food are limited by the availability of detailed food consumption data for all member states. A proposed comprehensive European dietary exposure model (CEDEM) applies summary data published by the European Food Safety Authority (EFSA) in a deterministic model based on an algorithm from the EFSA intake method for food additives. The proposed approach can predict estimates of food additive exposure provided in previous EFSA scientific opinions that were based on the full European food consumption database.     

Trace contamination of foods by migration from plastics packaging—A review

Plastic packaging often contains many components in addition to the base polymer. Additives are required both for the manufacturing process to give acceptable results and for the finished product to have the desired characteristics. Furthermore, decomposition products may arise from these additives, while the base polymer itself will contain monomer and oligomers in addition to traces of constituents of the polymerisation mixture (such as catalysts) and any decomposition products arising from these. Printing inks, laminates and their adhesives further complicate the picture. Consequently, the final product can contain a multitude of components at all levels from traces to perhaps 20–30% by weight.Where these components are of low molecular weight, a potential exists for their migration into packaged foods. It is essential, therefore, that manufacturers and users of plastic packaging intended for food contact be aware of the chemical nature of the range of potential migrants expected from a given polymer/additive/food system and have some understanding of the underlying mechanisms and kinetics of migration.This paper presents an overview of current knowledge of migration. After an outline of the physical basis of migration, the concept of—and problems inherent in—measuring overall migration are described, followed by a discussion of selected specific migrants.Although information on contamination from residual monomers forms the bulk of the available literature on specific migrants, migration of other base polymer constituents and of non-volatile plastics additives and their decomposition products can be of importance and is reviewed here.     

外卖食品接触材料中有害物质迁移研究进展

近年来外卖行业发展迅速,随之产生的食品接触材料安全问题也不容忽视。食品接触材料（FCM）由于反应副产物、低聚物、降解过程、包装材料与食品之间的化学反应或生产所用原料中的杂质而含有有害物质,在与食品接触时这些物质会迁移至食品中从而对人体造成危害。常见外卖食品接触材料为塑料与纸制品,其中含有塑化剂、抗氧化剂、光稳定剂等添加剂,而传统中式食品又以高温、高油食品为主,在使用一次性餐具盛装该类外卖食品时,添加剂极可能迁移到相关外卖食品中,具有较大的安全风险与隐患。本文对常见外卖食品接触材料中主要有害物质的性质、检测方法与迁移研究现状进行简述,了解外卖食品接触材料中有害物质的迁移情况,从而给外卖食品接触材料的安全监管提供一定的参考依据。     

Food and beverage can coatings: A review on chemical analysis,migration, and risk assessment

The internal surface of food and beverage cans is generally covered with polymeric coatings to preserve food and protect metal substrate from corrosion. Coating materials are complex formulations that contain different starting substances (e.g., monomers, prepolymers, additives, etc.) and in addition during the manufacture of the material several compounds can be formed (e.g., reaction products, degradation products, etc.). These substances have the potential to migrate into the food. Many of them have not been identified and only some have been toxicologically evaluated. This article aims to provide a comprehensive review on the analytical methods used for the identification of potential migrants in can coatings. The migration and exposure to chemicals migrating from can coatings are also reviewed and discussed so far, which is essential for risk assessment. Moreover, a brief section on the current status of the legislation on varnishes and coatings for food contact in Europe is also presented. Liquid chromatography coupled to diode array and fluorescence detectors and particularly to mass spectrometry and gas chromatography–tandem mass spectrometry seem to be the techniques of choice for the identification of potential migrants in can coatings. Some studies have reported migration levels of BPA (bisphenol A) and BADGE (bisphenol A diglycidyl ether) and derivatives exceeding the specific migration limits set in the European legislation. On the whole, low dietary exposure to migrants from can coatings has been reported. However, it is interesting to highlight that in these studies the combined exposure to multiple chemicals has not been considered.     

Stability testing of selected plastics additives for food contact in EU aqueous, fatty and alternative simulants

Within the framework of the AIR3-CT94-2360 EUproject, the stability of three plastics additives in three EU aqueous and fatty food simulants and in two alternative simulants was studied under various timetemperature conditions. The additives tested were bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) phthalate (DEHP) and octadecyl 3-(3,5-di- tert -butyl4-hydroxyphenyl) propionate (Irganox 1076). The various test conditions included exposures of 10 days at 40 o C, 1h at reflux temperature for all aqueous simulants, 10 days at 40 o C and 1h 175 o C for the olive oil and 2 days at 20 o C and 3h at 60 o C for the isooctane simulant. Following the exposure, the additive samples were extracted from aqueous simulants with hexane. A sonication step was necessary to ensure maximum extraction of control samples. In the case of the isooctane simulant, the samples were analysed directly from the simulant. The oil samples were extracted by acetonitrile. The extracts of samples exposed to various heat conditions as well as unexposed spiked controls and blanks were analysed by gas chromatography (GC) on a non-polar (5% -phenyl)-methylpolysiloxane capillary column with high temperature capabilities. The results showed that DEHA, DEHP and Irganox 1076 were stable at 40 o C and at reflux temperature in ethanolic or acidic aqueous simulants. The various additives were also stable in the organic isooctane simulant as well as in the fatty simulant olive oil. Studies on the stability of such additives used in food packaging are designed for regulatory purposes as an aid to decide whether the legislation should regulate limits for plasticizers based on a quantity in the food packaging itself or based on an ingested dose by the consumer.     

Qualitative identification of permitted and non-permitted colour additives in food products

Colour additives are dyes, pigments or other substances that can impart colour when added or applied to food, drugs, cosmetics, medical devices, or the human body. The substances must be pre-approved by the US Food and Drug Administration (USFDA) and listed in Title 21 of the US Code of Federal Regulations before they may be used in products marketed in the United States. Some also are required to be batch certified by the USFDA prior to their use. Both domestic and imported products sold in interstate commerce fall under USFDA jurisdiction, and the USFDA's district laboratories use a combination of analytical methods for identifying or confirming the presence of potentially violative colour additives. We have developed a qualitative method for identifying 17 certifiable, certification exempt, and non-permitted colour additives in various food products. The method involves extracting the colour additives from a product and isolating them from non-coloured components with a C₁₈ Sep-Pak cartridge. The colour additives are then separated and identified by liquid chromatography (LC) with photodiode array detection, using an Xterra RP18 column and gradient elution with aqueous ammonium acetate and methanol. Limits of detection (LODs) ranged from 0.02 to 1.49?mg/l. This qualititative LC method supplements the visible spectrophotometric and thin-layer chromatography methods currently used by the USFDA's district laboratories and is less time-consuming and requires less solvent compared to the other methods. The extraction step in the new LC method is a simple and an efficient process that can be used for most food types.     

EVALUATION OF PLASTICS PACKAGING MATERIALS FOR FOOD PACKAGING APPLICATIONS: FOOD SAFETY CONSIDERATIONS

In evaluating a packaging system for food packaging applications, consideration must be given to the physical properties, chemical composition and extractivity of the packaging material. The last point, extractivity, or migration from the packaging material to a food contact phase, is of major concern in the selection and use of plastics packaging materials for food packaging.
The present article deals specifically with migration of indirect food additives from plastics packaging materials and the scientific principles related to migrant transport or diffusion, as they apply to food safety. These principles and their experimental basis are discussed.     

Qualitative identification of permitted and non-permitted colour additives in food products

Colour additives are dyes, pigments or other substances that can impart colour when added or applied to food, drugs, cosmetics, medical devices, or the human body. The substances must be pre-approved by the US Food and Drug Administration (USFDA) and listed in Title 21 of the US Code of Federal Regulations before they may be used in products marketed in the United States. Some also are required to be batch certified by the USFDA prior to their use. Both domestic and imported products sold in interstate commerce fall under USFDA jurisdiction, and the USFDA's district laboratories use a combination of analytical methods for identifying or confirming the presence of potentially violative colour additives. We have developed a qualitative method for identifying 17 certifiable, certification exempt, and non-permitted colour additives in various food products. The method involves extracting the colour additives from a product and isolating them from non-coloured components with a C(18) Sep-Pak cartridge. The colour additives are then separated and identified by liquid chromatography (LC) with photodiode array detection, using an Xterra RP18 column and gradient elution with aqueous ammonium acetate and methanol. Limits of detection (LODs) ranged from 0.02 to 1.49 mg/l. This qualititative LC method supplements the visible spectrophotometric and thin-layer chromatography methods currently used by the USFDA's district laboratories and is less time-consuming and requires less solvent compared to the other methods. The extraction step in the new LC method is a simple and an efficient process that can be used for most food types.     

Plastics used in food packaging and the rôle of additives

Whilst paper and derived products still dominate packaging and large quantities of glass are still used in containers, the usage of plastics is significant, particularly for food packaging. Plastics are advantageous in providing good barrier properties in packages of low density (low weight) and high durability at low cost.Primary packaging of foodstuffs utilises film and containers principally; secondary packaging involves a wider variety of forms, including tote boxes and crates. In a cost-sensitive market, the commodity thermoplastics—polyolefins, poly(vinyl chloride) and styrene plastics—are widely employed in food packaging but there is considerable application of more expensive polymers in more advanced forms for special requirements.Satisfactory plastics packaging should not adversely affect the food in contact with it. Whilst pure high polymers might be expected to be inert, residual monomer, residues from polymerisation ancillaries, adventitious impurities and deliberate additives, all of lower molecular weight than the polymer, might be migratory and require particular consideration.