MIGRATION OF STYRENE MONOMER FROM THERMOSET POLYESTER COOKWARE INTO FOODS DURING HIGH-TEMPERATURE APPLICATIONS

Migration of styrene from thermoset polyester cookware into foods has been studied during normal cooking applications and for the fatty food simulant olive oil under high temperature test conditions. The analys is of foods was by automated headspace gas chromatography/mass spectro metry (GC/MS) in the selected ion mode. Cyclohexane was added to the s lurried foods to improve headspace partition and deuterated-styrene wa s the internal standard. To achieve adequate sensitivity with olive oi l, styrene was extracted and concentrated by a steam distillation meth od and then determined by GC/MS. Styrene in foods cooked in thermoset polyester articles was in the range <5 to 5 mug/kg and 5 to 30 mug/kg where the polyester contained 9 and 380 mg/kg residual monomer respect ively. Testing for 2 h at 175-degrees-C into olive oil resulted in sig nificantly higher migration of styrene than seen for other foods, alth ough there was a marked decrease in migration on repeat-use. Testing o f the complete articles as sealed systems filled with olive oil led to higher migration than testing by total immersion of plaques. Of the t est methods used with olive oil, testing as filled articles with no li dding gave migration results closest to (but generally higher than) th ose seen for real foods.