Mr. Chinawat Tongchat and Mr. Piriya Srichao, scientists from Department of Science Service (DSS) participated in the training program “Analysis of Surrogate Substances from Challenge Test in rPET” during 4 – 8 September 2023 at the laboratory of Aragon Institute for Engineering Research, University of Zaragoza, Spain. The training aimed to provide the analytical technique for determining of the surrogate substances, including Chlorobenzene (Volatile polar substance), Toluene (Volatile non-polar substance), Benzophenone (Non-volatile polar substance) and Phenylcyclohexane (non-volatile non-polar substance) in recycled polyethylene terephthalate (rPET) to evaluate the decontamination efficiency of recycling process of PET for reproducing FCM by challenge test according to EU guideline.