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

Abstract

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.

Keywords:

• toxicity
• mixtures
• exposure
• migrants
• risk
• food contact materials
• maximum cumulative toxicity

Funding

The presented work was supported by The Dow Chemical Company and ExxonMobil Biomedical Sciences.

Notes

^1. In the case of volatiles, the concentration of non-intentionally added substances (NIAS) is measured in the film (see text). Calculation of the concentration of NIAS in food is as follows:

The equation is based on the standard assumptions that an average adult person eats typically 1 kg food per day and that the food is packed in 6 dm² of plastic packaging film with a thickness of 250 µm. This results in a volume of 15 cm³ of film. Assuming a specific gravity of 1, this corresponds to 15 g of plastic. Hence, 1000 g of food will be packed in 15 g of plastic. Assuming that all the NIAS in the plastic enters the food, the concentration of NIAS in the food will be 67-fold lower than the concentration in the plastic.