Analysis of the Presence of Styrene in paperboard

Abstract

In this work, the presence of styrene in paperboard was studied. Styrene is used in the production of styrene-acrylate (SA) and styrene-butadiene (SB) latexes. SA- and SB-latexes are the most common binders used in the coating of paper and paperboard. Pigment coating with latex can improve the appearance and printability of the product, and dispersion coating can additionally bring a barrier property to the surface, e.g., grease resistance, water resistance, or air permeability. If some chemicals in the food contact material may transfer to the food, it is called migration. Currently, styrene can be used as a monomer or other starting material in food contact materials without a set migration limit. The European Commission is currently evaluating the possible establishment of a migration limit for styrene into food. Styrene may possibly be a genotoxic compound. Since styrene is a volatile organic compound, it was studied with a headspace gas chromatography, based on the method used in Metsä Board Corporation, for which this work was done. All the results are clearly below the considered possible specific migration limit. However, the method was not suitable for quantifying styrene at these concentrations. The aim of the study was to determine the amount of residual styrene in paperboard samples and to test how time, temperature and UV light affect the amount of residual styrene. The results show that the amount of residual styrene decreases over time, but UV light has insignificant effect on the amount of residual styrene.