Summary of the Public Health Goal for 1,2-Dichlorobenzene (1,2-DCB)
A Public Health Goal (PHG) of 0.6 mg/L (600 ppb) is developed for 1,2-dichlorobenzene (1,2-DCB) in drinking water. There is inadequate evidence to establish the carcinogenicity of 1,2-DCB to humans, and therefore the proposed PHG is based on noncarcinogenic adverse effects observed in experimental animals in a subchronic oral exposure study. The use of this study is consistent with the U.S. Environmental Protection Agency (U.S. EPA) in the establishment of its MCL for drinking water exposure. The National Toxicology Program (NTP) study cited numerous adverse effects in rats exposed to 250 and 500 mg/kg-day for 90 days which included hepatotoxicity and organ and body weight changes. These types of effects are consistent with other reports on the toxicity of 1,2-DCB. The no-observed-adverse-effect-level (NOAEL) for 1,2-DCB was identified as 125 mg/kg-day. Based on these data, OEHHA develops a PHG of 0.6 mg/L (600 ppb) for 1,2-DCB in drinking water.
- 1,2-Dichlorobenzene