## 5 Conclusions  
In the present study, the residual levels and the migration of styrene from intermediate and final food contact PS materials into food simulants and in yoghurt were assessed. Migration testing was performed with extruded sheets and thermoformed pots in 50% ethanol for 10 days at 40 \({}^{\circ}\)C and in 20% ethanol for 10 days at 40 \({}^{\circ}\)C and 20 \({}^{\circ}\)C, as well as in yoghurt after storage at 8 \({}^{\circ}\)C for 50 days. From an evaluation of the data obtained, the following conclusions can be drawn:* The residual styrene content in the PS materials correlates with the migration values and is far below a total transfer assumption.
* Styrene migration levels, measured in food simulants and in yoghurt, from intermediates (i.e., extruded sheets) were higher than those found in the final materials (i.e., thermoformed pots) and exceeded the precautionary specific migration limit (SML) for styrene of 40 \(\mathrm{\SIUnitSymbolMicro g}\)/kg, as proposed by the EU Commission [5].
* Styrene migration from pots, using conventional food simulants and under the test conditions specified in Regulation (EU) No. 10/2011 for refrigerated dairy products (50% ethanol for 10 days at 40 \({}^{\circ}\)C), overestimates the styrene migration values compared to its migration into food (yoghurt) under real-life storage conditions.
* Styrene migration from PS pots into yoghurt after storage at 8 \({}^{\circ}\)C for 50 days reached up to 15 \(\mathrm{\SIUnitSymbolMicro g}\)/kg (applying the EU cube model), which would be conservatively covered by testing the PS pots with 20% ethanol at 10 days/20 \({}^{\circ}\)C.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app14199056/s1](https://www.mdpi.com/article/10.3390/app14199056/s1)]([https://www.mdpi.com/article/10.3390/app14199056/s1](https://www.mdpi.com/article/10.3390/app14199056/s1)), Scanning electron microscopy (SEM) images of PS pots and sheets and exemplary chromatograms.  
Conceptualization, V.G.; data curation, V.G., A.G., D.F. and V.H.; formal analysis, A.G., V.H. and D.F.; funding acquisition, V.G., A.S. and F.W.; investigation, V.G., A.G., D.F. and V.H.; methodology, V.G.; project administration, V.G., A.S. and F.W.; supervision, A.S. and F.W.; validation, V.G. and A.S.; visualization, V.G., A.S. and F.W.; writing--original draft, V.G.; writing--review and editing, V.G., A.S. and F.W. All authors have read and agreed to the published version of the manuscript.  
This research received financial support from the Styrenics Steering Committee of Plastics Europe.  
Not applicable.  
The data used to support the findings of this study can be made available by the corresponding author upon request.  
The authors gratefully acknowledge financial support from the Styrenics Steering Committee of Plastics Europe. Thanks are due to [PERSON] (Systox Ltd.) for fruitful discussions and proofreading of the manuscript.  
The authors declare no conflicts of interest. The funders had no role in the design of the study, in the collection, analysis, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.