A03066: Investigation into the affect of additives on the migration of substances originating from colourants used in food contact plastics

Study Duration: October 2007 to Winter 2009

Contractor: Pira International

The Agency funded project A03045, "Identify chemicals that could migrate into foodstuffs from pigments and dyes and measure migration of these chemicals," published in November 2005, provided an important first step in identifying the substances that are most likely to migrate from colourants used in plastic packaging for food. Plastic test samples were prepared specially for this work and, in general, low levels of migration were found.

To avoid over-complexity, a variable that was not investigated in this initial work, was the effect on the migration of these substances by other additives that are usually present in plastics, in particular slip and anti-static agents. These ‘bloom’ to the surface of plastics in order to prevent them sticking together. They have low solubility in the polymer and the way they bloom cannot be predicted by theory, so cannot be modelled. There are no published data describing how these additives affect the migration of other substances present in plastics, however it is possible that the process of ‘blooming’ could exaggerate migration.

Based on advice gained in a meeting with industry representatives, relevant colourants will be obtained from 2-3 different world-wide sources and screened for potential migrants.
Plastics test samples will be prepared using some of the selected colourants and incorporating additives commonly used in plastic formulations. The additives selected will be slip and anti-static agents and other substances, such as colourant carriers that could influence migration. Migration from the test samples will be tested using appropriate food simulants and test conditions and the values compared against those obtained from plaques prepared without additives.