Ecological risk assessment of an antifouling biocide triphenyl (octadecylamine) boron in the Seto Inland Sea, Japan

In this study, we derived the predicted no-effect concentrations (PNEC) for triphenyl (octadecylamine) boron (TPB-18) and investigated the occurrence of triphenylboranes (TPBs), including TPB-18, for ecological risk assessment in the Seto Inland Sea, Japan. We tested algal growth inhibition, crustacean immobilization, and reproductive toxicity and performed toxicity tests in fish to assess acute and chronic toxicity and generate the PNEC for TPB-18. The minimum toxicity value was 0.30 μg/L, as determined by the 72-h no-observed-effect concentration (NOEC) for the alga Chaetoceros gracilis. The 5th-percentile of hazardous concentration (HC5), derived from NOECs using the species sensitivity distributions approach, was 0.059 μg/L, which indicated the PNEC of 0.0059 μg/L. In comparison, the highest concentration in seawater sampled from the Seto Inland Sea was 0.00034 μg/L, suggesting that the ecological risks posed by TPB-18 are currently low. •Acute and chronic toxicity was detected in marine organisms.•The minimum toxicity value was 0.30 μg/L, 72-h NOEC for Chaetoceros gracilis.•PNEC was estimated to be 0.0059 μg/L via the SSD approach using NOECs.•The highest concentration of TPBs in the environmental seawater was 0.00034 μg/L.•Ecological risk of TPB-18 is considered to be low in the Seto Inland Sea, Japan.