The purpose of the compatibility test is to evaluate the migration of chemicals between the cosmetic product and its container – primary packaging. Packaging can directly affect finished product stability and safety because of the possible physical and chemical interactions between the product, the package, and the external environment.
The Compatibility test may include:
- Interaction between the product and the container;
- Barrier properties of the container;
Several aspects are checked for both the container and the product:
- Waterproofness of the container;
- Phthalate concentration in the product;
- Aging of the container;
- Stability of the emulsion: there can be 2 phases formed for a product if it is unstable or if there are interactions between the packaging and the product. To check for the stability, the sample is observed both in the original packaging and in a glass (inert) container.
- Restitution test: to check that the whole product is accessible to the user considering its packaging
- Transportation test