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

Abstract

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.

Migrants from food cans revisited – application of a stochastic model for a more realistic assessment of exposure to bisphenol A diglycidyl ether (BADGE)

“…The consumption data include high consumers, the protection of whom has always been a priority for the EU, EFSA and industry. The surveys were either 4 or 7 days (for further details consult Holmes et al 1 ). The three surveys showed that 884 272 individual food items were consumed in total.…”

“…In earlier papers we have described the development of a two-dimensional probabilistic model to estimate the short-term dietary exposure to chemical migrants from food packaging materials 1 and the application of this model to estimate exposure to a generalized migrant from light metal packaging -principally food cans. 2 In the current work we have extended the application of the model to the specific question of the migration of bisphenol A diglycidyl ether (BADGE).…”

“…The mathematical details of the model are described elsewhere. 1 In essence, triangular distributions for unknown parameters and values between the lower and upper limits are randomly selected, with more values being chosen around the most likely value. The model is run for a large number of iterations (typically 1000), with a different value being used for each iteration.…”

Report of ESCO WG on non‐plastic Food Contact Materials

“…2008;Poças et al, 2009;Foster et al, 2010). Probabilistic approaches have been applied for coupling exposure assessment (Holmes et al, 2005) and migration modelling (Poças et al, 2010). According to a probabilistic study, changes in eating habits over time have a smaller impact on dietary exposure to migrants than changes in packaging usage, packaging composition and migration levels (Northing et al, 2009).…”

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

“…One of the main issues is that the current method in the EU is viewed as being overly conservative and does not give any indication of the true or real exposure to a food packaging migrant. To refine the exposure assessment, progress has been made in relation to the use of probabilistic exposure assessment modeling to estimate exposure to a food packaging migrant (Holmes et al 2005). This methodology accounts for variability and uncertainty in the exposure assessment and provides a more realistic exposure based on available data and on expert opinion.…”