Abstract: During the COVID-19, excessive use of disinfectants led to a large amount of disinfection by-products (DBPs) entering natural waters, which could have an adverse effect on the freshwater eco-environment. Five kinds of haloacetic acids (HAAs), including monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid, were studied. According to the EU Technical Guidance Document on Risk Assessment, the values of PNEC of 5 HAAs were derived in the water and sediment with the toxicity data of native species in China using assessment factors and equilibrium method, respectively. The results show that the acute and chronic toxicity of the 5 HAAs to aquatic organism were both in the order of monobromoacetic acid > monochloroacetic acid > dichloroacetic acid > trichloroacetic acid > dibromoacetic acid. The PNEC values of five HAAs for water (PNEC_w) were 0.025, 0.030, 0.060, 0.016 and 1.956 mg/L, respectively; for sediment (PNEC_s) are 0.021, 0.026, 0.057, 0.013 and 1.679 mg/kg (by wet weigh), respectively. This research shows that the DBPs in the effluents of wastewater treatment plants may pose potential risks and harms to the aquatic environment. Therefore, the monitoring and removal of five HAAs in the effluents of the WWTPs should be improved to reduce the concentration of HAAs discharged into natural waters.