## 4 Discussion
Among these, the notes on the verification of compliance N.22 state that \"when used in contact with non-alcoholic foods for which Table 2 of Annex III assigns food simulant D1, food simulant C (20% ethanol) shall be used for verification of compliance instead of food simulant D1\". This recommendation followed an EFSA Scientific Opinion [26], in which it was noted when the compliance of polyethylene furanoate (PEF) polymer is verified with 50% ethanol, interactions (i.e., swelling) between this food simulant and the plastic can occur, which would not take place in real food contact applications. A similar situation might be stated for polystyrene. As expected, the migration results from the tested food simulants and from the yoghurt confirm that the migration of styrene depends on its residual content in the PS materials, with migration from grades with higher styrene residuals resulting in higher migration and vice versa. Moreover, as previously reported, the migration of styrene depends on the ethanol content of the food simulant and the temperature used [13; 15; 20; 24; 27]. This applies to both pots and sheets. However, the level of migration from the extruded sheets was found to be clearly higher than that from the thermoformed pots (solid bars versus dashed bars in Figure 1). This confirms our findings in a previous study [20]. The migration of styrene in 50% ethanol from the sheets ranged between 188 and 241 \(\mu\)g/6 dm\({}^{2}\) and from the pots between 155 and 212 \(\mu\)g/6 dm\({}^{2}\). In 20% ethanol tested at 10 days/40 \({}^{\circ}\)C, it ranged between 83 and 116 \(\mu\)g/6 dm\({}^{2}\) for the sheets and between 65 and 98 \(\mu\)g/6 dm\({}^{2}\) for the pots. The migrations in 50% and 20% ethanol, tested at 10 days/40 \({}^{\circ}\)C, from the pots were only 12-22% lower than those of the corresponding sheets (produced with identical PS grades). The migration levels in 20% ethanol, tested at 10 days/20 \({}^{\circ}\)C, ranged between 38 and 68 \(\mu\)g/6 dm\({}^{2}\) from the sheets and between 16 and 22 \(\upmu\)g/6 dm\({}^{2}\) from the pots. This means that in these conditions, the migration from the pots is approx. 58-70% lower than that of the corresponding sheets. The styrene migration in food simulants exceeded the predicted precautionary SML for styrene of 40 \(\upmu\)g/kg for all the tested sheets. When testing the pots with food simulants, the results exceeded this limit, with the exception of the conditions for 20% ethanol of 10 days/20 \({}^{\circ}\)C.  
Similarly, the migration of styrene in yoghurt from the extruded sheets was found to be higher than that from the thermofermed pots. The migration from pot PS-P-11 was half of the one obtained from sheet PS-S-11. The migration from the other pots, PS-P-22 and PS-P-32, was 80% lower than that in the corresponding sheets (produced with the identical PS grades). At a temperature of 8 \({}^{\circ}\)C, the migration in yoghurt from the sheets with the higher styrene residual content (PS-S-22 and PS-S-32) already exceeded 40 \(\upmu\)g/6 dm\({}^{2}\) after 20 days of storage, reaching 73 \(\upmu\)g/6 dm\({}^{2}\) and 94 \(\upmu\)g/6 dm\({}^{2}\) after 50 days. It was only from the sheet with the lowest residual styrene content (PS-S-11) that migration did not exceed this limit. Additionally, only for this sheet, the migration seemed not to increase over time (in contrast to the other two sheets; see Figure 2). This finding might be due to surface effects that were possibly caused by the converting process during the manufacture of this sheet, which might have affected the surface of the material and caused a different migration behavior compared to the other two sheets. When testing the pots with yoghurt, migration remained below or at 15 \(\upmu\)g/6 dm\({}^{2}\), even after 50 days of storage at 8 \({}^{\circ}\)C. All the pots complied with the SML of 40 \(\upmu\)g/kg that has been proposed for styrene.