Chronic effects of bisphenol S and bisphenol SIP on freshwater waterflea and ecological risk assessment.

Bisphenol S (BPS) and 4-hydroxyphenyl 4-isoprooxyphenylsulfone (BPSIP) have been used as substitutes for bisphenol A (BPA) owing to increased regulation of BPA in plastics. In this study, long-term toxicity tests of BPS and BPSIP were performed using Daphnia magna and Moina macrocopa. The predicted no-effect concentration (PNEC) of BPA, BPS, and BPSIP were derived by the assessment factor (AF) method and the species sensitivity distribution (SSD) method. An ecological risk assessment was performed based on the measured environmental concentrations of BPA in surface water worldwide and the derived PNECs. The chronic NOEC of D. magna was 2.5 mg/L for BPS and 0.5 mg/L for BPSIP, and that of M. macrocopa was 0.03 mg/L for BPS and 0.1 mg/L for BPSIP. The PNEC was generally one order of magnitude less than the PNEC, and the PNEC of BPS was 10 times lower than that of BPA. The hazard quotients of BPA and BPS exceeded 1, indicating that concentrations in ambient water conditions could pose a potential risk to aquatic organisms. Since the use of alternative compounds is increasing, further monitoring data of the water environment and chronic toxicity in various aquatic organisms appears to be necessary.