Cross Border Polymer Migration Testing Standard Parameters
Cross-border polymer migration compliance requires testing finished articles under verified worst-case simulants, contact times, and surface-to-volume ratios.
Repeat Contact Testing
Meaning
Laboratory testing methods that simulate multiple successive uses of a plastic article evaluate how chemical migration changes over the product’s lifespan. In the evaluation of reusable kitchenware or medical devices, repeat contact testing requires exposing the same plastic sample to three consecutive portions of food simulant. The compliance of the material is based on the migration measured during the third exposure.
This protocol determines if the plastic becomes more or less stable after repeated washing and use.
Testing Protocol
The plastic article is filled with food simulant and kept at the specified temperature for the required contact time. This simulant is then poured out and analyzed. The process is repeated twice more with fresh simulant, and the migration levels of the three phases are compared.
Migration Dynamics
In many polymers, migration decreases with each successive exposure as the residual chemicals on the surface are washed away. However, if the polymer degrades or swells, migration can increase over time. This provides crucial information about the long term safety of the material.
Regulatory Rule
Under European rules, the migration measured in the third test must be below the specific migration limit. If migration increases between the second and third tests, the material cannot be approved for repeat use, even if the absolute values remain below the limit.