Stability testing of selected plastics additives for food contact in EU aqueous, fatty and alternative simulants

Within the framework of the AIR3-CT94-2360 EU-project, the stability of three plastics additives in three EU aqueous and fatty food simulants and in two alternative simulants was studied under various time-temperature conditions. The additives tested were bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) phthalate (DEHP) and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox 1076). The various test conditions included exposures of 10 days at 40 degrees C, 1 h at reflux temperature for all aqueous simulants, 10 days at 40 degrees C and 1 h 175 degrees C for the olive oil and 2 days at 20 degrees C and 3 h at 60 degrees C for the isooctane simulant. Following the exposure, the additive samples were extracted from aqueous simulants with hexane. A sonication step was necessary to ensure maximum extraction of control samples. In the case of the isooctane simulant, the samples were analyzed directly from the simulant. The oil samples were extracted by acetonitrile. The extracts of samples exposed to various heat conditions as well as unexposed spiked controls and blanks were analysed by gas chromatography (GC) on a non-polar (5%--phenyl)-methylpolysiloxane capillary column with high temperature capabilities. The results showed that DEHA, DEHP and Irganox 1076 were stable at 40 degrees C and at reflux temperature in ethanolic or acidic aqueous simulants. The various additives were also stable in the organic isooctane simulant as well as in the fatty simulant olive oil. Studies on the stability of such additives used in food packaging are designed for regulatory purposes as an aid to decide whether the legislation should regulate limits for plasticizers based on a quantity in the food packaging itself or based on an ingested dose by the consumer.