Hexachlorocyclopentadiene
Metropolitan District Commission
Hexachlorocyclopentadiene was historically used for the manufacture of currently banned pesticides, such as endrin, dieldrin and chlordane. It’s still used for production of flame retardants, resins and plastics.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | ND | 7 | 0 | ND |
| 2019 | N/A | 0 | 0 | N/A |
| 2020 | ND | 3 | 0 | ND |
| 2021 | ND | 3 | 0 | ND |
| 2022 | ND | 3 | 0 | ND |
| 2023 | ND | 3 | 0 | ND |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 2 ppb
The EWG Health Guideline of 2 ppb for hexachlorocyclopentadiene 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 the stomach and intestines.
EPA Maximum Contaminant
Level (MCL): 50 ppb
The legal limit for hexachlorocyclopentadiene, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-06-27 | CA79476 | ND |
| 2018-06-27 | CA79477 | ND |
| 2018-06-27 | CA79475 | ND |
| 2018-09-25 | CB38504 | ND |
| 2018-09-25 | CB38505R | ND |
| 2018-09-25 | CB38869 | ND |
| 2018-09-25 | CB38505 | ND |
| 2020-12-08 | SOC 200600638 | ND |
| 2020-12-08 | SOC 200600609 | ND |
| 2020-12-09 | SOC 200600592 | ND |
| 2021-11-23 | S300107511 300107513 | ND |
| 2021-11-23 | S300107593 300107596 | ND |
| 2021-11-29 | S300109627 300109629 | ND |
| 2022-12-15 | S300287039 300287044 | ND |
| 2022-12-15 | S300287062 300287065 | ND |
| 2022-12-15 | S300287090 300287093 | ND |
| 2023-12-05 | S300456329 300456332 | ND |
| 2023-12-06 | S300456308 300456311 | ND |
| 2023-12-06 | S300456298 300456301 | ND |