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.

We have used a two-dimensional probabilistic model to estimate the short-term dietary exposure of UK consumers to bisphenol A diglycidyl ether (BADGE) migrating from light metal food packaging. Using three UK National Dietary and Nutrition Surveys comprising 4-7-day dietary surveys for different ages and genders, actual body weights and survey years, a sample representative of the UK population was obtained, comprising around 4200 food items. The packaging type of each food item was assigned by utilizing known packaging type from the database or by sampling from a distribution based upon market share information or expert judgement. For concentration data, we have used published data for foods or food simulants or a combination of both. The probabilistic approach allowed sensitivity analysis to evaluate the relative importance of the input parameters and placed confidence bounds on the outputs to show the effect of the uncertainties. The refined estimates gave an exposure for UK consumers, at the 97.5th percentile level, of 0.41-0.83 mg/kg body weight (bw)/day for the different age ranges and scenarios run. All estimates are well below the new tolerable daily intake value of 150 mg/kg bw/day for BADGE and its two hydrolysed forms, and are also well below the restriction value of 17 mg/kg bw/day for the other regulated BADGE derivatives. The main contributors to exposure are beverages, along with aqueous and acidic foods. This is because of the high consumption of these classes of foodstuffs, even though levels of migration into these foodstuffs and into their appropriate simulants is normally non-detectable. Reducing the non-detectable level six-fold reduced the estimate of exposure by 40-60%.

A two-dimensional probabilistic model was constructed to estimate the short-term dietary exposure of UK consumers to any generalized migrant from coated light metal food packaging. Using three UK National Dietary and Nutrition Surveys (NDNS) comprising 4-7-day dietary surveys for different age and gender groups, actual body weights and survey years, a sample representative of the dietary consumption of the UK population was obtained comprising around 4,200 food items. Interrogation of the raw data showed that the per capita consumption of food and beverage for an adult was 2.9 kg per person day(-1), which is comparable with the US FDA value of 3.0 kg. The packaging type of each food item was assigned from the survey descriptions or by sampling from distributions based upon market share information and expert judgement. Each food item was assigned to the relevant food simulant: A (aqueous), B (acidic) or D (fatty), so that simulant migration data could be used. The exposure model was used to evaluate exposure for a given level of migration and, conversely, the level of migration that could be tolerated whilst keeping within a target threshold exposure level. As examples, migration at 10 microg dm(-2) into fatty foods only resulted in an exposure ranging from 0.06 to 0.22 microg kg(-1) body (actual) weight day(-1) depending on the scenario. The model revealed that if migration from metal coatings was only into fatty foods, migration in the range 1.83-4.95 microg dm(2) (97.5th percentile, depending on the scenario) would give an exposure of less than 1.5 microg per person day(-1). This is a toxicological threshold limit used in the USA. If migration into simulants A and B is also considered to be at the same level as that for simulant D, then the level of migration for the threshold to be reached is, not surprisingly, lower (0.64-0.87 microg dm(-2)) than that if migration were only into fatty foods. In this case, clearly the main contributors to the exposure were foodstuffs represented by simulants A and B because of their importance in the diet. These estimates are based on 4- or 7-day food diaries and chronic exposure over the long-term would be expected to be lower.