Determination of the extractable components of reusable microwavable food containers in the New Zealand marketplace

Abstract

Leaching of polymer additives into food products has been well documented, with recent studies reporting increased migration when exposed to microwave irradiation. Toxicological assessments of additives and associated degradation products have found potential links to estrogenic and reprotoxic activity. As such, there is a growing concern regarding the safety of plastic food contact materials. Studies on reusable microwave food containers are limited. In New Zealand, studies have focused on additives in commercial food products. No studies specific to reusable food containers available in the New Zealand marketplace were found. This present study aimed to determine leachable components of commercially available microwave plastic food containers to assess potential health risks. An initial non-targeted screening was carried out on eleven polypropylene and Tritan™ copolyester microwave food containers using gas chromatography mass spectrometry. Thirty five additives were tentatively identified, not including hydrocarbons. Further migration studies were carried out using deionized water as a food simulant and extracted by liquid-liquid extraction. Repeated exposure to microwave irradiation was used to simulate consumer behavior. Overall, low levels of leachables were observed in the food simulant extracts. However, semi-quantification of degradation products indicated concentrations exceeding the specific migration limit established by the European Union. Three of the eleven containers may be considered non-compliant under these experimental conditions and should be investigated further.