Stability testing of the plastics additives 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-ethoxy-2-ethyloxanilide (tinuvin 312) and 2,2'-methylenebis(4-methyl-t-tert-butyl phenol) in aqueous and fatty food simulants.

The stability of five additives used in the manufacture of plastics materials intended to be in contact with foodstuffs was tested in two EU aqueous food simulants (3% acidic acid and 15% ethanol), in olive oil and in two alternative fatty food simulants (95% ethanol and isooctane) under various conditions of temperature and time established for migration testing. The additives were the following: 2,4-dihydroxybenzophenone, 2-2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-ethoxy-2-ethyloxanilide and 2,2'-methylenebis(4-methyl-6-tert-butyl phenol). The additives were spiked into the simulants at their anticipated Specific Migration Limit (SML) and submitted to time-temperature conditions used in the migration testing. The test samples were analysed against fresh samples of the additives spiked at the same concentration just before the analysis. All samples were analysed with HPLC, using an ODS2 column and mobile phase of methanol-water or acetonitrile-water. The results were statistically evaluated by applying a two-tailed F-test (at 95% confidence level) to the variances and onetailed t-test (at 90% confidence level) to the means of the control and the test samples. The statistical evaluation of the results showed that the additives were stable in all simulants within the statistical allowances. Only the 2.2'-methylenebis(4-methyl-6-tert-butyl phenol) showed a loss of about 20% in olive oil and 17% in 3% aqueous acetic acid. The results of the study will be used by the Commission, DG III-C-I. to help to determine whether legislative restrictions in the additives Directive should be applied to the finished material or article (QM) or to migration to simulants (SML).