V. Komolprasert et al., MIGRATION OF RESIDUAL CONTAMINANTS FROM SECONDARY RECYCLED POLY(ETHYLENE-TEREPHTHALATE) INTO FOOD-SIMULATING SOLVENTS, AQUEOUS-ETHANOL AND HEPTANE, Food additives and contaminants, 14(5), 1997, pp. 491-498
This study measured the migration of benzene, butyric acid, dodecane,
octadecane, tetracosane, diazinon, lindane, and copper(II) ethyl hexan
oate from poly(ethylene terephthalate) (PETE) sheets into the food sim
ulants, 8% ethanol/water and n-heptane, The contaminated PETE sheets w
ere extruded from PETE chips that had been previously contaminated but
were washed, dried, and remelted. The level of these contaminants rem
aining in the extruded sheets ranged from benzene at 0.6 mg/kg to copp
er salt at 24 mg/kg. The extraction data demonstrate that migration of
the residual contaminants from the extruded PETE sheets resulted in c
oncentrations lower than 10 mu g/kg in the food simulants. At very hig
h residual concentrations of butryic acid (147 mg/kg) and benzene (218
mg/kg) in sheets made from unwashed PETE, higher amounts of the conta
minant migrated into the food simulants. This migration resulted in co
ntaminant concentrations exceeding 10 mu g/kg and suggests that unwash
ed recycled PETE may not comply with FDA reguirements. The crystallini
ty of extruded PETE sheets in this study ranged from 5 to 15%, which i
s lower than that of most commercial PETE (30%). Therefore, the migrat
ion data obtained from these test samples represent the most severe co
nditions for conservative exposure evaluations.