title: Suitability of polystyrene as a functional barrier layer in coloured food contact materials.
abstract: Functional barriers in food contact materials (FCMs) are used to prevent or reduce migration from inner layers in multilayer structures to food. The effectiveness of functional barrier layers was investigated in coloured polystyrene (PS) bowls due to their intended condition of use with hot liquids such as soups or stew. Migration experiments were performed over a 10-day period using USFDA-recommended food simulants (10% ethanol, 50% ethanol, corn oil and Miglyol) along with several other food oils. At the end of the 10 days, solvent dyes had migrated from the PS bowls at 12, 1 and 31,000 ng cm(-)(2) into coconut oil, palm kernel oil and Miglyol respectively, and in coconut oil and Miglyol the colour change was visible to the human eye. Scanning electron microscope (SEM) images revealed that the functional barrier was no longer intact for the bowls exposed to coconut oil, palm kernel oil, Miglyol, 10% ethanol, 50% ethanol and goat's milk. Additional tests showed that 1-dodecanol, a lauryl alcohol derived from palm kernel oil and coconut oil, was present in the PS bowls at an average concentration of 11 mg kg(-1). This compound is likely to have been used as a dispersing agent for the solvent dye and aided the migration of the solvent dye from the PS bowl into the food simulant. The solvent dye was not found in the 10% ethanol, 50% ethanol and goat's milk food simulants above their respective limits of detection, which is likely to be due to its insolubility in aqueous solutions. A disrupted barrier layer is of concern because if there are unregulated materials in the inner layers of the laminate, they may migrate to food, and therefore be considered unapproved food additives resulting in the food being deemed adulterated under the Federal Food Drug and Cosmetic Act.
authors.affiliation: a Center for Food Safety and Applied Nutrition , US Food and Drug Administration , College Park , MD , USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Genualdi
authors.forename: Susana
authors.initials: S
authors.lastname: Addo Ntim
authors.forename: Timothy
authors.initials: T
authors.lastname: Begley
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents / Q000032:analysis*; D055032:Electron Microscope Tomography; D005504:Food Analysis; D005506:Food Contamination / Q000032:analysis*; D018857:Food Packaging; D017408:Guidelines as Topic; D011137:Polystyrenes / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D004396:Coloring Agents; D011137:Polystyrenes
keywords: functional barrier; migration; polystyrene