Occurrence of volatile organic compounds (VOCs) and phthalate acid esters (PAEs) in recycled PET: Implications for food packaging materials

Abstract

The growing use of recycled polyethylene terephthalate (rPET) in food packaging has raised concerns about the presence of non-intentionally added substances (NIAS), particularly volatile organic compounds (VOCs) and phthalic acid esters (PAEs). This study aimed to characterize and quantify these compounds in PET and rPET materials across different processing stages (flakes, granules, and preforms), representing a comprehensive view of the recycling cycle. Results showed a clear increase in the concentration of NIAS in rPET compared to virgin PET (vPET). The most prevalent NIAS identified were with ethylene glycol, 2-methyl-1,3-dioxolane, benzaldehyde, benzene, dibutyl phthalate (DBP), and dimethyl phthalate (DMP). Notably, samples with higher recycled content exhibited significantly greater levels of both VOCs and PAEs, indicating a direct relationship between recycling intensity and chemical contamination. Unlike previous studies, which have largely focused on migration from finished bottles, this work provides a direct assessment of contaminant levels in the material itself. These findings emphasize the need for stricter control and monitoring of recycling processes. Future research should address the development of NIAS reduction strategies to ensure the safety of recycled plastics in food contact applications.