Safety-Health :

According to a plastic food service products website of the American Chemistry Council :

Based on scientific tests more than five decades, government safety agencies have determined that polystyrene is safe for use in foodservice products. For example, polystyrene meets the standards of the U.S. Food and Drug Administration and the European Commission/European Food Safety Authority for use in packaging to store and serve food. The Hong Kong Food and Environmental Hygiene Department lately reviewed the safety of serving several foods in polystyrene foodservice products and reached the same result as the U.S. FDA.
Between 1999 till 2002, a comprehensive review of the potential health risks associated with exposure to styrene was conducted by a 12 member international expert panel selected by the Harvard Center for Risk Assessment. The scientists had expertise in toxicology, epidemiology, medicine, risk analysis, pharmacokinetics, and exposure assessment.
The Harvard study conveyed that styrene naturally exists in fruit and foods such as strawberries, beef, and spices, and is naturally produced in the processing of foods such as wine and cheese. The study also reviewed all the published data on the quantity of styrene contributing to the diet due to migration of food packaging and reusable food contact articles, and concluded there is no cause for concern for the general public from exposure to styrene from foods or styrenic materials used in food-contact applications, such as polystyrene packaging and food service containers.
Polystyrene is common container for food and drinks. The styrene monomer (from which polystyrene is made) is a cancer suspect agent; it is "generally found in such low levels in consumer products that risks are low".
Styrene in food or water can quickly enter the body through the digestive tract and most of these chemicals are excreted in urine within a few days. Styrene is highly metabolized in humans, with an estimated 97% removed through metabolic pathways.
cause of the universal use of polystyrene, these health related issues remain topical.
Styrene oligomers in polystyrene containers used for food packaging have been found to transfer into the food. Another Japanese study conducted on wild-type and AhR-null mice found that the styrene trimmer, which the authors discovered in cooked polystyrene container-packed instant foods, may increase thyroid hormone levels.