Styrene migration from expanded polystyrene boxes into fresh cod and redfish at chilled and superchilled temperatures
The aim of the experiment was to investigate the possible flow of styrene from foam plastic boxes to fresh cod and redfish fillets, which are stored at typical temperatures during sea transport of fresh fillets from Iceland to Europe or America. US buyers want fish fillets to be packed in plastic bags before packing in a foam box due to possible styrene contamination from foam to fish. Therefore, in this project, styrene was measured in fish, which had been stored without plastic bags in foam boxes, and the amount of styrene was compared with the standards of the US Food and Drug Administration (FDA). A total of 12 foam boxes containing cod or redfish fillets were stored for 4, 7 or 13 days at either -1 ° C or 2 ° C, which corresponds to the optimal and highest probable temperature in fresh fillet shipping. One 10-50 g sample was taken from the lower part of the bottom fish fillet in each box and had thus been in direct contact with foam plastic and therefore placed in a glass bottle. Subsequently, the 12 samples were sent for analysis to Eurofins, an international laboratory in Germany. The results show that the amount of styrene, as well as other undesirable substances such as benzene and toluene, was below 0.01 mg / kg fish in all twelve fish samples. The FDA guideline (maximum) is 90 mg of styrene per kg of fish per person per day, which is equivalent to The result of this experiment is that a consumer has to consume 9000 kg of fish daily to meet the FDA standard, which is a very unrealistic amount. The main conclusion of this experiment is that it is not necessary to pack fresh fish fillets in plastic bags for packing in foam boxes, which are stored and transported in refrigerated and supercooled conditions.
The aim of the study was to investigate possible styrene migration from expanded polystyrene into fresh cod and redfish, two important export fish species in Iceland, while stored under conditions mimicking transport by ship from Iceland to America and Europe. American buyers wish to have a plastic bag between EPS boxes and fish during transport as a safety measure due to possible styrene migration. Thus, this project was conducted to investigate if adding a plastic bag is necessary with regards to safety limits for styrene migration from packaging to food set by the FDA (US Food and Drug Administration). A total of twelve samples of cod and redfish were stored in EPS boxes manufactured by Tempra ltd. for 4, 7 and 13 days at two temperatures (-1 ° C, 2 ° C) which represent optimal and expected maximum storage temperatures during sea transport of fresh fish. A sample of 10-50 grams of fish, which had been in direct contact with the packaging, was taken from the bottom of each box, as it is considered the most hazardous place regarding styrene migration, and put in a glass bottle before analysis. Finally, the twelve samples of fish were sent to Eurofins, an international laboratory in Germany, for analysis. The results show that styrene content, and other solvent residues like benzene or toluene, were below 0.01 mg / kg in all twelve samples of fish. The FDA's daily intake limit of styrene is 90 mg / kg per person per day, which means that in this study an unrealistic intake of at least 9000 kg of fish would be necessary to exceed this FDA´s limit. The main conclusion from this study is therefore that a plastic bag is not needed to safely pack cod and redfish fillets into EPS boxes to be stored under chilled and superchilled temperatures.