According to Plastics Europe data, 29.1 mio tons of plastics were collected from household waste in the year 2018, but only less than 1/3 of this was sent for recycling. The remaining part was directed to thermal treatment and energy recovery or landfilled. There is currently a major drive by the plastics industry to increase the proportion of recyclate streams and thus establish a circular economy. Polystyrene (PS) is frequently used in food packaging due to its property profile and its good processability and is therefore also found in household waste. At the same time, PS has unique advantages in terms of material reuse: PS is spectroscopically well detectable and can therefore be easily separated from other fractions in sorting processes. It can be dissolved in certain selective solvents and thus recovered as a highly pure macromolecule. Furthermore, the polymer chain can be split back into its monomers comparatively easily and thus pure styrene monomer can be recovered as a starting point for new PS grades. Overall, PS exhibits excellent preconditions for recycling. On the technological side, high purity mechanical recycling, as well as dissolution of PS and chemical recycling via depolymerisation are all possible solutions. All 3 processes can produce recyclates that are approved for food contact. In the work presented here, these 3 technologies are for the first time assessed in comparable scenarios regarding their environmental impacts compared to established thermal treatment using the methodology of life cycle assessment. The waste and the product perspective as well as a combination of both approaches are considered. Considering the avoided incineration and also the fossil-based material, which can be replaced, all technologies reveal tremendous impacts on reduction of global warming potential of more than 75 %. In absolute values HIPS granules produced via recycling save app. 900 to > 1500 kg CO2 (e) per ton PS depending on the recycling technology used.