Gas Chromatographic/Mass Spectrometric Determination of Benzene in Nonstick Cookware and Microwave Susceptors and Its Migration into Foods on Cooking

Abstract

Benzene in poly(tetrafluoroethylene) (PTFE) coatings of nonstick cookware was determined by heating a small amount of coating in a sealed vial. Gas chromatography/mass spectrometry (GC/MS) was used to analyze the vial headspace for benzene. A small survey (26 samples) of retail nonstick cookware detected benzene ranging from 2 to 50 micrograms/dm2 in 7 samples. Nonstick frying pans with various polymer coatings were obtained directly from 1 manufacturer. Benzene (6-30 micrograms/dm2) was detected in a number of these samples and was attributed to the use of a phenylmethyl silicone ingredient that contained benzene at 360 mg/kg. To determine the possible transfer of benzene from these coatings during normal use, several foods (puddings, cakes, and roast potatoes) were prepared in previously unused cookware. The foods were analyzed by using static headspace GC/MS. Benzene was not detected in any of these foods at a limit of detection of 2 micrograms/kg. In related studies, the determination of benzene release from microwave susceptors was performed by heating the materials in a sealed system at 190 degrees C for 4 min. Benzene release above 1 microgram/dm2 was not detected in 24 samples of susceptors. However, 1 specially supplied sample of non-metallized susceptor released 10 micrograms/dm2 benzene when heated above normal anticipated temperatures of usage (to 220 degrees C). Foods such as french fries and pizza when cooked according to the manufacturer's instructions in susceptors contained no benzene with a limit of detection of 2 micrograms/kg. Even under abuse conditions of susceptors, the transfer of benzene to foods remained below this limit.