o-Dichlorobenzene
San Francisco City Water System
o-Dichlorobenzene is used as a chemical intermediate for making agricultural herbicides. It is toxic to the liver, kidneys and the nervous system, and causes cancer in animal studies.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | ND | 1 | 0 | ND |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 17 | 0 | ND |
| 2019 | ND | 4 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 600 ppb
The EWG Health Guideline of 600 ppb for o-dichlorobenzene was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to internal organs.
EPA Maximum Contaminant
Level (MCL) 600 ppb
The legal limit for o-dichlorobenzene, established in 1991, was based on a toxicity study in laboratory animals conducted in the 1970s.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2016-06-14 | 9553-001-0920 | ND |
| 2018-01-11 | 9553-007-1115 | ND |
| 2018-03-06 | 9590-004-1031 | ND |
| 2018-03-08 | 9590-006-0925 | ND |
| 2018-04-17 | 9590-007-1055 | ND |
| 2018-04-30 | 9590-008-1013 | ND |
| 2018-06-12 | 9590-008-0930 | ND |
| 2018-06-12 | 9590-004-1058 | ND |
| 2018-07-17 | 9590-007-0519 | ND |
| 2018-07-26 | 9553-006-0838 | ND |
| 2018-09-12 | 9590-004-0944 | ND |
| 2018-09-25 | 9553-006-0930 | ND |
| 2018-09-25 | 9553-004-0910 | ND |
| 2018-09-25 | 9553-008-0950 | ND |
| 2018-10-17 | 9553-007-0730 | ND |
| 2018-12-11 | 9553-004-0845 | ND |
| 2018-12-11 | 9553-006-0915 | ND |
| 2018-12-11 | 9553-008-1045 | ND |
| 2019-06-17 | 9553-008-1106 | ND |
| 2019-06-17 | 9553-007-0905 | ND |
| 2019-06-17 | 9553-006-1206 | ND |
| 2019-06-17 | 9553-004-0956 | ND |