Prediction of Two Isothiazolinone Biocides Migrating from Coated Paper into Liquid Food Simulants and Assessment of Human Exposure

Abstract

A simple method to detect the initial concentration of two isothiazolinone biocides (5-chloro-2-methylisothiazol-3(2H)-one (CMI) and 2-methylisothiazol-3(2H)-one (MI)) in 17 kinds of coated paper food packaging samples by ultrasonic assistant extraction coupled with liquid chromatography-tandem mass spectrometry (LC-MS) was established. MI and CMI were detected in 5 samples with the concentrations ranging from 397.6 to 1789μg/kg. Paper is a heterogeneous material and these two biocides are polar substances which means there is an affinity between two biocides and cellulose, so the mathematical model can be used to simulate the migration process. Considering their relatively low initial content in coated paper, AKTS-SML software was used to simulate the migration of CMI and MI from paper through polyethylene coating into food simulants. Piringer model was used to predict the diffusion of CMI and MI in paper and polyethylene, both partition coefficient between paper and polyethylene and between polyethylene and food simulants were set to 1. The Cumulative Estimated Daily Intake (CEDI) of MI or CMI migrated from coated paper were below 0.084mg/60kg/day and 0.1023 mg/60kg/day, indicating a negligible exposure risk.