The interactions between packaging and formulations are still, and again, a major topic! Which exchanges between these intertwined components can be looked for? What is released by one of them, absorbed by another? What are the consequences of the potential damage done to any of them? Right, the packaging/contents interactions are at the heart of many concerns, especially since they have been fingered out in regulatory documents, as in the Article 17 and the Annex I of the new Regulation. This was the topic of the paper given by Benoît Persin (Intertek) during the 26th Breakfast Meetings - Cosmetics.