Estimation and verification of the environmental fate ofO-Benzyl-p-chlorophenol

O-Benzyl-p-chlorophenol (OBPC) has widespread use in the United States as a hospital phenolic disinfectant; annual production averages less than 4.5×106 kg. Disposal is primarily via municipal waste treatment where biodegradation removes 95% of the OBPC as confirmed by modeling and field measurements. Measured influent and effluent concentrations from 16 sites in the United States averaged 14.8 μg/L and 0.8 μg/L, respectively. These measured data confirm the utility of the Holman model (1981) for predicting the concentration of household chemicals during sewage treatment. OBPC is apparently rapidly metabolized by fish and has a low potential to bioconcentrate in biota (bioconcentration factor for OBPC is 75). Based upon laboratory studies, biodegradation and photolysis are the major transformation processes in the environment; hydrolysis and volatilization rates are insignificant. The five percent of the total OBPC reaching the aquatic environment was predicted by two models to partition to the water column resulting in average surface water concentrations of 0.001–0.008 μg/L. Environmental sampling at 18 sites in the eastern United States confirmed that the average concentration in surface waters was <0.11 tμg/L.