Polyphenylene sulfide (PPS) chopsticks are valued for their heat resistance; however, food‐contact safety research has predominantly focused on common plastics such as polyethylene and polypropylene, neglecting the effect of cooking conditions on specialty plastics. This study aimed to systematically investigate the release of dichlorobenzene (DCB) isomers (1,2‐, 1,3‐, and 1,4‐DCB) from PPS chopsticks at cooking temperatures. Fourier transform infrared spectroscopy (FTIR) and field‐emission scanning electron microscopy (FESEM) confirmed polymer matrix integrity and revealed surface oxidation at 160°C and micro‐cracks at 200°C, elucidating pathways for DCB migration. A three‐dimensional (3D) response‐surface‐optimized high‐performance liquid chromatographic (HPLC) method afforded a limit of detection (LOD) of 0.05 mg L −1 and a limit of quantification (LOQ) of 0.15 mg L −1 for each isomer, with a correlation coefficient of > 0.999, recovery of > 90%, and intraday precision of < 2%. Olive‐oil simulant tests (175°C, 2 h) detected 1,4‐DCB in 4 of 14 new batches, challenging the “200°C‐safe” claim and underscoring the need for batch‐specific verification. Our findings provide the first systematic evidence of DCB migration from PPS tableware, providing a rigorous analytical framework to improve food‐contact material safety and inform regulatory standards for developing heat‐resistant plastics.
Zhong et al. (Thu,) studied this question.