Alternative Method for Determination of Over-All Migration from Plastic Wares Intended to Come into Contact with Food

As stipulated in the regulation of (EU) 10/2011, for determination of over-all migration from plastic wares intended to come into contact with food, the sample should be immersed in simulated liquor at 40 ℃ for 10 days. Aiming to shorten the testing time, conditions of immersion of different kinds of plastics in various simulated liquor under different temperatures with a shorter time were tested, and the following procedures were proposed: ① immerse in mixture of C2H5OH-H2O (10+90) at 100 ℃ for 88 h;② immerse in CH3COOH-H2O (3+97) at 100 ℃ for 6 h;③ immerse in C2H5OH-H2O (95+5) at 60 ℃ for 40 h;④ immerse in iso-octane at 60 ℃ for 5 h. At the end of immersion, the simulated liquor was removed to an evaporating dish (weighed to constant mass of m1 previously), and evaporated to dryness. The dish together with the residue was placed in an oven (at 105 ℃) overnight and its mass was weighed to constant (m2). Value of all-over migration was calculated by m2-m1/volume of simulated liquor. By using either of the 4 modified immersion conditions, not only the testing time was shortened, and the results were also found to meet with the requirements of the relative regulations.