Interlaboratory investigation of NIAS with non-targeted methods: need for harmonisation.

Non-intentionally added substances (NIAS) pose significant challenges in the analysis of food contact materials, particularly due to the lack of standardised screening methodologies. This study presents an interlaboratory investigation comparing the efficacy of headspace gas chromatography-mass spectrometry (GC-MS), GC-MS/FID, and liquid chromatography-high-resolution mass spectrometry (LC-(HR)MS) in identifying and quantifying NIAS. In total 13 participating laboratories were requested to apply their in-house commercial method to analyse a plastic laminate. Migration in Tenax and 50% ethanol and extraction were requested. Results revealed inconsistencies across the laboratories, primarily attributable to variations in analytical techniques, analytical standards selected, libraries used, and reporting practices. Notably, improved consistency was observed when aligned methodologies were employed, highlighting the necessity for standardisation in non-targeted screening processes. The findings suggest that a method to achieve consistent results below 0.1 mg/kg food may be more difficult to achieve making it challenging to meet the requirements from the recent European Commission Regulation 2025/351 on purity criteria. This highlights a critical need for harmonised approaches to enhance the reliability of NIAS screening.