In vitro hazard characterization of contaminants migrating from recycled paper food contact materials

The safety of paper food contact materials (FCMs) is critical for public health, necessitating precise toxicity assessments. This study investigates the impact of sample preparation methods (migration and extraction), liver metabolic enzymes, endogenous ligands, and various cell lines on the in vitro toxicity of paper FCMs. Toxicological endpoints include mutagenicity, genotoxicity, potential estrogenicity, androgenicity, aryl hydrocarbon receptor activity, and cytotoxicity to hepatocytes and the colon intestinal epithelial barrier, using HepG2 and Caco-2 cell lines. Two preparation methods were employed: migration per Commission Regulation (EU) October 2011 and exhaustive Soxhlet extraction. Extraction revealed distinct toxicological profiles compared to migration, exhibiting toxicity in more endpoints, potentially due to different sample conditions affecting chemical identity and concentration. The addition of liver metabolic enzymes altered estrogenic and androgenic activity, while endogenous ligands influenced potency in estrogenicity and androgenicity tests. Integrating extraction and migration methods with physiologically relevant models enhances the evaluation of hazards from paper FCMs. This involves incorporating cell lines that mimic target tissues, such as liver and intestinal epithelium, alongside metabolic enzymes and endogenous ligands in estrogen receptor alpha and androgen activity testing, providing a strategy for the comprehensive assessment of hazards in food contact materials.