Dietary exposure to chemical migrants from food contact materials: A probabilistic approach

A two-dimensional probabilistic model has been developed to estimate the short-term dietary exposure of UK consumers to migrants from food packaging materials. The current EU approach uses a default scenario of assuming that all individuals are 60 kg weight and consume 1 kg of food packaged in the material of interest per day. Using four UK National Dietary and Nutrition Surveys comprising 4-7 day dietary records for different age groups and survey years, a sample representative of the UK population has been obtained consuming around 4200 different food items. Each survey provides records for around 2000 individuals and supplies detailed information on the consumption of food and data on sex, height and socio-economic status which may be used to analyse the exposure of selected groups within the community. As a result we are able to address the variation in consumption of food amongst individuals, and account for actual body weights providing a more accurate representation of the 'true' exposure. The migrants bisphenol A diglycidyl ether (BADGE), di-2-ethylhexyl adipate (DEHA) and styrene were considered as specimen compounds although the methodology employed has the flexibility to adapt to other migrants and packaging types and indeed other food contaminants. Exposure for each individual is estimated by calculating and summing the individual exposure from each item in their diet, and is repeated for all individuals in each survey to produce a distribution of exposures for the population. The packaging type of each food item is assigned by utilizing known packaging types from the database or, by sampling from a distribution based upon market share information. The parameters contributing towards the exposure from a packaged dietary item are migrant concentration and item weight. Distributions are used to represent the inherent variation and uncertainty affecting these parameters. Where data on concentrations for a particular type of food are lacking, expert judgement is used to extrapolate from available data for other food types. The model can also be run using only migration data for food simulants. In this case, concentrations expected for each of the food items are assigned based on the data for the relevant food simulant. The primary outputs of the model are distributions of estimated daily intakes for the selected population. Each distribution gives the variation across the population subject to the uncertain parameters sampled in that iteration of the model. Analysing the ensemble of distributions allows us to obtain the confidence limits around estimates for percentiles due to the uncertainties. The probabilistic approach allows sensitivity analysis to evaluate the relative importance of the input parameters and places confidence bounds on the outputs to show the effect of the uncertainties and the contribution of each food type toward the overall exposure.     

Estimates of dietary exposure to bisphenol A (BPA) from light metal packaging using food consumption and packaging usage data: a refined deterministic approach and a fully probabilistic (FACET) approach

The FACET tool is a probabilistic model to estimate exposure to chemicals in foodstuffs, originating from flavours, additives and food contact materials. This paper demonstrates the use of the FACET tool to estimate exposure to BPA (bisphenol A) from light metal packaging. For exposure to migrants from food packaging, FACET uses industry-supplied data on the occurrence of substances in the packaging, their concentrations and construction of the packaging, which were combined with data from a market research organisation and food consumption data supplied by national database managers. To illustrate the principles, UK packaging data were used together with consumption data from the UK National Diet and Nutrition Survey (NDNS) dietary survey for 19–64 year olds for a refined deterministic verification. The UK data were chosen mainly because the consumption surveys are detailed, data for UK packaging at a detailed level were available and, arguably, the UK population is composed of high consumers of packaged foodstuffs. Exposures were run for each food category that could give rise to BPA from light metal packaging. Consumer loyalty to a particular type of packaging, commonly referred to as packaging loyalty, was set. The BPA extraction levels used for the 15 types of coating chemistries that could release BPA were in the range of 0.00005–0.012 mg dm^–2. The estimates of exposure to BPA using FACET for the total diet were 0.0098 (mean) and 0.0466 (97.5th percentile) mg/person/day, corresponding to 0.00013 (mean) and 0.00059 (97.5th percentile) mg kg^–1 body weight day^–1 for consumers of foods packed in light metal packaging. This is well below the current EFSA (and other recognised bodies) TDI of 0.05 mg kg^–1 body weight day^–1. These probabilistic estimates were compared with estimates using a refined deterministic approach drawing on the same input data. The results from FACET for the mean, 95th and 97.5th percentile exposures to BPA lay between the lowest and the highest estimates from the refined deterministic calculations. Since this should be the case, for a fully probabilistic compared with a deterministic approach, it is concluded that the FACET tool has been verified in this example. A recent EFSA draft opinion on exposure to BPA from different sources showed that canned foods were a major contributor and compared results from various models, including those from FACET. The results from FACET were overall conservative.     

US FDA's revised consumption factor for polystyrene used in food-contact applications

US FDA's continual effort to evaluate the safety of food-contact materials includes periodically re-examining our established packaging factors, such as consumption and food-type distribution factors. The use of polystyrene in food-contact and disposable food-packaging applications has expanded and is expected to continue to increase in the future. Therefore, it is important to revise the polystyrene consumption factor to account for increases in consumer exposure to substances migrating from styrenic food packaging. The currently used consumption factor for polystyrene is 0.1, which is based on market data collected around 1980. US FDA has revised the polystyrene consumption factor utilizing three different sources of market data. Using consumption and population data, US FDA calculated a new consumption factor of 0.14 for polystyrene. This consumption factor has been further subdivided to allow for the refinement of exposure estimates for uses limited to specific subcategories of polystyrene packaging.     

Tiered intake assessment for food colours

ABSTRACT

A tiered intake assessment approach, ranging from the conservative default and refined budget method to refined dietary exposure assessments using national food consumption surveys is presented and applied to derive maximum potential global colour intake estimates. The US and UK markets served as representative for the world and the EU, respectively, to determine the maximum potential exposure ceilings for eleven colours in various sub-populations, including brand-loyal consumers. Industry-reported global use levels were assigned as the maximum level. Conservative intake assessments for food colours used in non-alcoholic beverages were estimated for the general population 2 + y, toddlers, children 3–9 y, adolescents 10–17 y, adults 18–64 y, elderly 65–74 y, very elderly 75 + y based on assumed uses in high intake markets. Refined dietary exposures were estimated using either the 2-day food consumption data from the 2013–2016 US National Health and Nutrition Examination Survey or the 4-day food consumption data from the 2008–2016 U.K. National Diet and Nutrition Survey Rolling Programme. In the most refined market-share adjusted assessment, brand-specific market volume data were used to place appropriate weight on corresponding beverage type uses. Strong concordance between the refined budget method and the brand-loyal deterministic approach was shown, in which the latter assumes that the maximum use level of the colour is present in 100% of non-alcoholic beverages. This study shows that safety of colours – both synthetic and natural – in beverages at proposed use levels can be supported for any geography, with all intake estimates falling below the acceptable daily intake in refined assessments. Importantly, this study demonstrates that the refined budget method is a valid first-tier screening assessment to prioritise food colours that may benefit from more refined intake assessments when warranted.     

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.     

Assessment of food intake input distributions for use in probabilistic exposure assessments of food additives

A key component of a food chemical exposure assessment using probabilistic analysis is the selection of the most appropriate input distribution to represent exposure variables. The study explored the type of parametric distribution that could be used to model variability in food consumption data likely to be included in a probabilistic exposure assessment of food additives. The goodness-of-fit of a range of continuous distributions to observed data of 22 food categories expressed as average daily intakes among consumers from the North-South Ireland Food Consumption Survey was assessed using the BestFit® distribution fitting program. The lognormal distribution was most commonly accepted as a plausible parametric distribution to represent food consumption data when food intakes were expressed as absolute intakes (16/22 foods) and as intakes per kg body weight (18/22 foods). Results from goodness-of-fit tests were accompanied by lognormal probability plots for a number of food categories. The influence on food additive intake of using a lognormal distribution to model food consumption input data was assessed by comparing modelled intake estimates with observed intakes. Results from the present study advise some level of caution about the use of a lognormal distribution as a mode of input for food consumption data in probabilistic food additive exposure assessments and the results highlight the need for further research in this area.     

Assessment of dietary exposure in the French population to 13 selected food colours,preservatives, antioxidants,stabilizers, emulsifiers and sweeteners

The results of French intake estimates for 13 food additives prioritized by the methods proposed in the 2001 Report from the European Commission on Dietary Food Additive Intake in the European Union are reported. These 13 additives were selected using the first and second tiers of the three-tier approach. The first tier was based on theoretical food consumption data and the maximum permitted level of additives. The second tier used real individual food consumption data and the maximum permitted level of additives for the substances which exceeded the acceptable daily intakes (ADI) in the first tier. In the third tier reported in this study, intake estimates were calculated for the 13 additives (colours, preservatives, antioxidants, stabilizers, emulsifiers and sweeteners) according to two modelling assumptions corresponding to two different food habit scenarios (assumption 1: consumers consume foods that may or may not contain food additives, and assumption 2: consumers always consume foods that contain additives) when possible. In this approach, real individual food consumption data and the occurrence/use-level of food additives reported by the food industry were used. Overall, the results of the intake estimates are reassuring for the majority of additives studied since the risk of exceeding the ADI was low, except for nitrites, sulfites and annatto, whose ADIs were exceeded by either children or adult consumers or by both populations under one and/or two modelling assumptions. Under the first assumption, the ADI is exceeded for high consumers among adults for nitrites and sulfites (155 and 118.4%, respectively) and among children for nitrites (275%). Under the second assumption, the average nitrites dietary exposure in children exceeds the ADI (146.7%). For high consumers, adults exceed the nitrite and sulfite ADIs (223 and 156.4%, respectively) and children exceed the nitrite, annatto and sulfite ADIs (416.7, 124.6 and 130.6%, respectively).     

Estimation of exposure to food packaging materials. 3: Development of consumption factors and food-type distribution factors from data collected on Irish children

There are many initiatives in Europe trying to refine the exposure assessment for food packaging migrants. In the USA, the US Food and Drug Administration (US FDA) uses food consumption and food-type distribution factors to aid the exposure assessment process and generate more realistic estimates of exposure. The present study developed food-consumption factors and food-type distribution factors for Irish children aged 5-12 years from data collected as part of a National Children's Food Survey (NCFS) completed in Ireland in 2003-04, combined with data from the 2003-05 Irish Food Packaging Database and from literature data on surface area-to-weight ratios for food packaging. Consumption factors are defined as the fraction of a person's diet likely to contact a specific food-contact material, while food-type distribution factors reflect the fraction of all food contacting each material that is aqueous, acidic, alcoholic or fatty. In this study, it was found that 'total plastics' had the highest consumption factor of 0.83, while 'total paper and board' had a factor of 0.13 and 'total metal and alloys' had a factor of 0.06. Although it is tentative to compare the US FDA factors with the factors derived in the current study, as the US FDA data are for the total US population, the consumption factor for 'total plastics' in the present study (0.83) was similar to that used by the US FDA (0.79). However, a large difference existed for the consumption factor for 'total metal and alloys' in the Irish data (0.06) and the US FDA data (0.2). In terms of the type of materials used for foods, glass was used mainly for acidic foods (0.67), while plastic was uniformly used for all food types. The food-contact area for plastic packaging for all foods consumed by children was 10.67 dm²/child day^-1, which is slightly lower than the proposed value for the average European consumer of 12.4 dm²/person day^-1. However, this should be expected, as children do not consume as much food as adults. When scenario exposure estimates were made, it was found that when using European Union assumptions, estimates were much larger than when using consumption factors and food-type distribution factors in the exposure assessment, even when conservative assumptions were employed for the consumption factor. This study highlights the potential use of consumption factors and food-type distribution factors in the refinement of the exposure assessment process and how these factors can be calculated using data collected as part of a national food survey.     

Assessment of the migration potential of nanosilver from nanoparticle-coated low-density polyethylene food packaging into food simulants

An experimental nanosilver-coated low-density polyethylene (LDPE) food packaging was incubated with food simulants using a conventional oven and tested for migration according to European Commission Regulation No. 10/2011. The commercial LDPE films were coated using a layer-by-layer (LbL) technique and three levels of silver (Ag) precursor concentration (0.5%, 2% and 5% silver nitrate (AgNO₃), respectively) were used to attach antimicrobial Ag. The experimental migration study conditions (time, temperature and food simulant) under conventional oven heating (10 days at 60°C, 2 h at 70°C, 2 h at 60°C or 10 days at 70°C) were chosen to simulate the worst-case storage period of over 6 months. In addition, migration was quantified under microwave heating. The total Ag migrant levels in the food simulants were quantified by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Mean migration levels obtained by ICP-AES for oven heating were in the range 0.01–1.75 mg l^?1. Migration observed for microwave heating was found to be significantly higher when compared with oven heating for similar temperatures (100°C) and identical exposure times (2 min). In each of the packaging materials and food simulants tested, the presence of nanoparticles (NPs) was confirmed by scanning electron microscopy (SEM). On inspection of the migration observed under conventional oven heating, an important finding was the significant reduction in migration resulting from the increased Ag precursor concentration used to attach Ag on the LDPE LbL-coated films. This observation merits further investigation into the LbL coating process used, as it suggests potential for process modifications to reduce migration. In turn, any reduction in NP migration below regulatory limits could greatly support the antimicrobial silver nanoparticle (AgNP)-LDPE LbL-coated films being used as a food packaging material.     

Time‐ and temperature‐dependent migration studies of Irganox 1076 from plastics into foods and food simulants

The study provides an exhaustive set of migration data for octadecyl 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionate (Irganox 1076) from low‐density polyethylene (LDPE) in several food matrices. Irganox 1076 was used as a model migrant because it represents one of the typical substances used as an antioxidant in food packaging polymers. Kinetic (time‐dependent) migration studies of Irganox 1076 were performed for selected foodstuffs chosen with different physical–chemical properties and in relation to the actual European food consumption market. The effect of fat content and of the temperature of storage on the migration from plastic packaging was evaluated. The results show that migration increased with fat content and storage temperature. All data obtained from real foods were also compared with data obtained from simulants tested in the same conditions. In all studied cases, the kinetics in simulants were higher than those in foodstuffs. The work provides data valuable for the extension of the validation of migration model developed on simulants to foodstuffs themselves.     

Lead exposure from food: the German LExUKon project

Lead is a highly toxic contaminant with food being the major source of exposure for the general public. The second German food consumption survey (Nationale Verzehrsstudie II – NVS II) with about 20 000 participants (15 371 for dietary history interviews used for this study) allowed for an updated exposure assessment for the German population. Based on these comprehensive data, information on consumption of 545 individual food items by the German population was generated. Lead concentrations in food were compiled from the German food monitoring programme, European countries’ authority programmes and the published literature, covering the years from 2000 to 2009, and were multiplied with consumption data to obtain estimates of lead intake from food. Average lead concentrations per main food group were highest for meat (including offal), followed by fish (including seafood), vegetables and cereals. Due to high consumption, beverages contributed most to the intake of the general public, followed by main groups vegetables, fruits & nuts and cereals. Lead intake from food was estimated to be 0.53 and 0.72 µg kg^–1 bw and day for average and high-end consumers, respectively. This is close to (average consumers) respectively above (high-end consumers) a reference value derived from a recent health risk evaluation performed by EFSA, using the benchmark approach. Uncertainties in these estimates pertain to the influence of values below the limit of quantification and some foods not considered due to lacking occurrence data. In conclusion, the estimated lead intake of the German population from food is still close to health-based reference values. Further efforts to reduce lead intake are required.     

采用ICP-MS研究聚酯类食品包装材料中锑向食品模拟物的迁移规律

目的 建立聚酯(PET)和4种食品模拟物中锑的电感耦合等离子体质谱(ICP-MS)测定方法.用该方法研究PET中的锑向水、10％(V/V)乙醇溶液、3％(W/V)乙酸水溶液和精炼橄榄油4种食品模拟物迁移的行为与浸泡时间、温度、食品模拟物属性、锑初始含量等参数的关系.方法 在不同的温度下,将不同的PET浸泡于食品模拟物中,于一定的时间点吸取少量浸泡液,用ICP-MS测定其含量.结果 ICP-MS方法回收率在94.3％ ～96.1％之间,相对标准偏差在1.38％ ～3.31％之间.结论 锑迁出量随温度升高而增加;随着时间的延长,锑迁出量逐渐增加,一定时间后达到迁移平衡;大部分PET材料本底含量越高迁出量越高;PET中锑易于在酸性食品模拟物中迁出,应少食用PET包装的酸性食品.     

Assessment of uncertainty in a probabilistic model of consumer exposure to pesticide residues in food

The assessment of consumer exposure to pesticides is an important part of pesticide regulation. Probabilistic modelling allows analysis of uncertainty and variability in risk assessments. The output of any assessment will be influenced by the characteristics and uncertainty of the inputs, model structure and assumptions. While the use of probabilistic models is well established in the United States, in Europe problems of low acceptance, sparse data and lack of guidelines are slowing the development. The analyses in the current paper focused on the dietary pathway and the exposure of UK toddlers. Three single food, single pesticide case studies were used to parameterize a simple probabilistic model built in Crystal Ball™. Data on dietary consumption patterns were extracted from National Diet and Nutrition Surveys, and levels of pesticide active ingredients in foods were collected from Pesticide Residues Committee monitoring. The effect of uncertainty on the exposure estimate was analysed using scenarios, reflecting different assumptions related to sources of uncertainty. The most influential uncertainty issue was the distribution type used to represent input variables. Other sources that most affected model output were non-detects, unit-to-unit variability and processing. Specifying correlation between variables was found to have little effect on exposure estimates. The findings have important implications for how probabilistic modelling should be conducted, communicated and used by policy and decision makers as part of consumer risk assessment of pesticides.     

Testing nano-silver food packaging to evaluate silver migration and food spoilage bacteria on chicken meat

Migration of nanomaterials from food containers into food is a matter of concern because of the potential risk for exposed consumers. The aims of this study were to evaluate silver migration from a commercially available food packaging containing silver nanoparticles into a real food matrix (chicken meat) under plausible domestic storage conditions and to test the contribution of such packaging to limit food spoilage bacteria proliferation. Chemical analysis revealed the absence of silver in chicken meatballs under the experimental conditions in compliance with current European Union legislation, which establishes a maximum level of 0.010 mg kg^–1 for the migration of non-authorised substances through a functional barrier (Commission Regulation (EU) No. 10/2011). On the other hand, microbiological tests (total microbial count, Pseudomonas spp. and Enterobacteriaceae) showed no relevant difference in the tested bacteria levels between meatballs stored in silver-nanoparticle plastic bags or control bags. This study shows the importance of testing food packaging not only to verify potential silver migration as an indicator of potential nanoparticle migration, but also to evaluate the benefits in terms of food preservation so as to avoid unjustified usage of silver nanoparticles and possible negative impacts on the environment.     

Core food model of the Taiwan food supply for total diet study

ABSTRACT

Following the core food (CF) models of the USA and France reported in the 2000s, this study presents the first oriental CF model, for total diet studies in Taiwan. First, we combined the four latest national dietary recall surveys from 2005 to 2012, data sets from the Nutrition and Health Survey in Taiwan (NAHSIT) covering all ages (1 to 65+ years old). In total, 3,098 NAHSIT food codes from 349,497 records of responses from 7,580 individuals were aggregated within a three-tiered scheme into 237 CFs in 54 subcategories and 16 categories. As with Western foods, Taiwanese foods were mainly aggregated by food type and major ingredient, processing method, cooking method or serving habit. In addition, we propose several categories typical to Taiwanese foods: (1) processed foods (e.g. rice paste, rice noodle, bean curd); (2) mixed foods (e.g. tomato fried with egg, Guangdong porridge) and stuffed staple foods (e.g. rice cake, zongzi); (3) Chinese Dim Sum (e.g. dumpling, salted bun); and (4) animal offal (e.g. pig liver, chicken kidney) and by-products (e.g. chicken head, pig foot). Systematic nomenclature and coding methods are also proposed. A computerised web model was developed using a graphical user interface (GUI) for automatic CF aggregation and inquiry of various consumption estimates according to the residing area, age group, and gender of consumers. Point estimates of weighted means were calculated for consumption rates (CR) based on the whole group (WG) or consumers only (CO). The CR and body weight (BW) of each individual were matched to calculate mean intake per unit body weight (g/kg bw/day). A general sample design procedure with the CF model is suggested for a total diet study (TDS) on target hazards. Strategies are also discussed for improving the quality of food matching in sample designs.     

食品及食品包装材料中塑化剂的检测研究进展

食品和食品包装材料中塑化剂对人体的危害不可小觑。本文主要介绍了食品及食品包装材料中塑化剂国内外检测标准、样品前处理方法及主要的检测方法。欧盟法规(EU)No 10/2011相对于以往的2002/72/EC对于迁移测试的要求整体趋于严格,生产企业有必要改进生产工艺以应对更新的测试规则。国家现有的标准中对于食品和食品包装材料中塑化剂有一定的要求,目前最常见的研究大部分为食品和食品包装材料中邻苯二甲酸酯类化合物,但对于其他类型的塑化剂检测结果相对较少,这也将是今后食品和食品包装材料中塑化剂检测研究的一个主要方向。     

Safety by design of printed multilayer materials intended for food packaging

ABSTRACT

Printing inks are commonly used in multilayer plastics materials used for food packaging, and compounds present in inks can migrate to the food either by diffusion through the multilayers or because of set-off phenomena. To avoid this problem, the right design of the packaging is crucial. This paper studies the safety by design of multilayer materials. First, the migration from four different multilayers manufactured using polyethylene terephthalate (PET), aluminium (Al) and polyethylene (PE) was determined. The structural differences among materials such as the presence of inks or lacquer coatings as well as the differences in layers position allowed the study of a safety-by-design approach. Sixty-nine different compounds were detected and identified; 49 of them were not included in the positive list of Regulation EU/10/2011 or in Swiss legislation and 15 belong to Cramer class III, which means that they have a theoretical high toxicity. Some of the compounds related to ink composition were pyrene, a compound commercially used to make dyes and dye precursors and the antioxidant Irganox 1300. The application of external lacquers decreased the concentration of some migrants but also brought the potential for new migrants coming from its composition. A final risk assessment of the material allowed evaluating food safety for different food simulants and confirm it.     

Cadmium exposure from food: the German LExUKon project

Cadmium is a very toxic contaminant with food being the major source of exposure for the general public. The second German food consumption survey (Nationale Verzehrsstudie II – NVS II) with about 20 000 participants (15 371 for dietary history interviews used for this study) allowed for an updated exposure assessment for the German population. Based on these comprehensive data, information on the consumption of 545 individual food items by the German population was generated. Cadmium concentrations in food were compiled from the German food monitoring programme, European countries’ authority programmes and the published literature, covering the years from 1993 to 2008, and were multiplied with consumption data to obtain estimates of cadmium intake from food. Consumption-weighted mean cadmium concentrations per main food group were highest for cereals, followed by oily seeds & fruits, and vegetables. Due to both high consumption and considerable occurrence of cadmium, cereals and vegetables contributed most to the intake of the general public, followed by the main groups beverages, fruits & nuts, and dairy products (including milk). Cadmium intake from food was estimated to be 1.46 and 2.35 µg kg^–1 bw week^–1 for average and high-end consumers, respectively. This corresponds to 58% for average and 95% for high-end consumers, respectively, of a reference value derived from a recent health risk evaluation performed by EFSA, using the benchmark approach. Uncertainties in these estimates pertain to the influence of values below the limit of quantification and some foods not considered due to lacking occurrence data. In conclusion, the estimated cadmium intake of the German population from food is still close to health-based reference values. Further efforts to reduce cadmium intake are required.