NIAS – Degradation Products

NIAS originating from antioxidants – Formation of degradation products in the polymer and during migration testing

Workgroup: Compliance of Packaging Material

Scientific partners and guidance:

  1. Fraunhofer Institut for Process Engineering and Packaging IVV, Petra Schmid and Carina Stärker

Financing: IVLV e.V.
Duration: 2019

Antioxidants are used in polymer materials in order to protect them from oxidative degradation (autoxidation) during their whole life time. Thereby, they can undergo oxidation or scavenge radicals formed in the polymer and thus yield smaller molecules as degradation products. Besides the intact antioxidants a polymer can thus also contain reaction or degradation products formed during manufacturing, processing or storage.
For antioxidants used in food contact materials the requirements of the European Plastics Regulation (EU) No 10/2011 apply. Degradation products of antioxidants are classified as non-intentionally added substances – "NIAS" and, just like the intact precursor, can potentially migrate into contacting food. In addition to a formation in the polymer, degradation of antioxidants can also take place in food simulants during migration testing or in the food itself. In cases where degradation products apart from those already contained in the polymer are formed in food simulants used for migration testing, but not in the food itself, the migration of NIAS is misrepresented and there is the potential that materials or articles are discriminated as being non-compliant based on the NIAS detected in a migration test. Vice versa, there is also the potential that migration testing with simulants underestimates the real migration into food due to degradation processes during the migration contact.
It has already been shown in the IVLV NIAS projects 2017 and 2018 that in particular migration tests with alternative fatty food simulants cause degradation of certain antioxidants at common migration test conditions. Therefore it shall be investigated whether this degradation also takes place in the food itself. Furthermore, it will be investigated to what extent the content or the chemical identity of the degradation products of antioxidants contained in the material is influenced by the storage or use of the plastic article (repeated use articles).