Interaction of a vinylic organosol used as can coating with solvents and food simulants

Metal cans are often protected from corrosion by vinylic organosol coatings , made from PVC and epoxyphenolic (EP) resins. Using electron spin resonanc e, BADGE, a monomer of EP, was shown to plasticize PVC. Optimization of ext raction allowed extraction of 4 mg of BADGE/dm(2), so vinylic organosols ap pear to be worst-case coatings. Comparison of behavior between BADGE and a paramagnetic probe revealed that these compounds were trapped to a large ex tent in the crosslinked EP network and could not migrate at 40 degrees C. C ontact with triglycerides, which plasticize the coating, induced high migra tion of BADGE. Neither isooctane nor ethanol could mimic fats, in contrast to isooctane/tert-butyl acetate mixtures. In aqueous foodstuffs, BADGE hydr olyzed into a monoepoxide and then into a bisdiol. The total amount of toxi cologically relevant epoxides over shelf life was shown to reach a maximum value within 3 weeks at 40 degrees C, at very low levels, whatever the aque ous food simulant. After sterilization at 120 degrees C (20 min), the level of BADGE in the migrate is very low, whereas up to 2 mg of hydrolysis prod ucts is found in the liquid/dm(2). During further storage at 40 degrees C, the amount of epoxides rapidly decreases.