Migration study of caprolactam from polyamide 6 sheets into food simulants.

Caprolactam, used in manufacturing polyamide (PA) 6, may threaten human health. Here, PA 6 sheets were produced by using a twin-screw extruder to evaluate its safety. Caprolactam migration concentrations from the PA 6 sheets into food simulants were evaluated according to the standard migration test conditions under the Korean Food Standards Codex (KFSC). Concentrations were investigated under various food simulants (distilled water, 4% acetic acid, 20 and 50% ethanol, and heptane) and storage conditions (at 25, 60, and 95 °C). Caprolactam migration concentrations into food simulants were determined as follows: 4% acetic acid (0.982 mg/L), distilled water (0.851 mg/L), 50% ethanol (0.624 mg/L), 20% ethanol (0.328 mg/L), and n-heptane (not detected). Migrations were determined to be under the regulatory concentration (15 mg/L) according to the KFSC test conditions. Taken together, these results verified that the standard migration test conditions by KFSC were reliable to evaluate the safety of PA 6.