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

Abstract

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.

Keywords: analytical techniques; exposure assessment; food metal cans; migration; polymeric coatings.