A scientific study on the long-term migration of diverse additives from the polyvinyl chloride (PVC) food can coatings was published online on January 11, 2016 in the Food Additives & Contaminants: Part A journal. Marta Vaclavikova and colleagues from the Center for Food Safety and Applied Nutrition of U.S. Food and Drug Administration (FDA) developed a rapid and sensitive mass spectrometry-based method to measure 21 selected migrants, including a cross-linking agent, slip agents, and plasticizers including phthalates, adipates, sebacates and epoxidized oils. The migration of these analytes into food simulants (water and 3 % acetic acid) stored at 40 °C was assessed for a period from 1 day to 1.5 years. For comparison, migration after storage at ambient temperatures for a period of 365 and 540 days was also assessed.
No migration into aqueous food simulants was detected for any of the analyzed plasticisers or slip agents, despite the low detection limits (5 ng/ml). On the contrary, a cross-linking agent benzoguanamine (BGA; CAS 91-76-9) was measured in all samples, with concentrations increasing with longer storage times and reaching a maximum of 84 µg/dm2 in 3 % acetic acid after storage at 40 °C for 1.5 years. BGA concentrations in deionized water stored at similar conditions were about two times lower and in the samples stored at ambient temperature 3-4 times lower compared to the ones stored at 40 °C.
The authors concluded that the short-term migration tests (10 days at 40 °C) would provide sufficient information about migration potential after longer storage, but only if the cans are not subjected to uneven or higher storage temperatures. If such suboptimal temperature conditions would be the case, then “the data obtained after 10 days of migration tests would not provide comprehensive information about total amount of BGA migration that could occur”. Hence, migration tests longer than 10 days and at higher temperatures may be necessary when assessing safety for food cans intended for long-term storage.
Reference
Vaclavikova, M. et al. (2016). “Target and non-target analysis of migrants from PVC-coated cans using UHPLC-Q-Orbitrap MS: evaluation of long-term migration testing.” Food Additives & Contaminants: Part A 33, 352-363.
