Hexachlorocyclopentadiene
City of Napa
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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | ND | 5 | 0 | ND |
| 2015 | ND | 6 | 0 | ND |
| 2016 | ND | 2 | 0 | ND |
| 2017 | ND | 3 | 0 | ND |
| 2018 | ND | 4 | 0 | ND |
| 2019 | ND | 2 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
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 |
|---|---|---|
| 2014-07-09 | 9590-007-0925 | ND |
| 2014-07-09 | 1233-007-0925 | ND |
| 2014-07-09 | 9590-006-1245 | ND |
| 2014-07-09 | 1233-006-1245 | ND |
| 2014-07-09 | 9590-005-1145 | ND |
| 2015-07-21 | 1233-007-0940 | ND |
| 2015-07-21 | 9590-007-0940 | ND |
| 2015-07-21 | 1233-005-1120 | ND |
| 2015-07-21 | 9590-006-1415 | ND |
| 2015-07-21 | 1233-006-1415 | ND |
| 2015-07-21 | 9590-005-1120 | ND |
| 2016-07-27 | 9590-006-1545 | ND |
| 2016-07-27 | 9590-006-1245 | ND |
| 2017-07-20 | 9590-006-1330 | ND |
| 2017-07-20 | 9590-007-1050 | ND |
| 2017-09-13 | 9590-005-0840 | ND |
| 2018-07-11 | 1233-006-1015 | ND |
| 2018-07-11 | 9590-006-1015 | ND |
| 2018-07-11 | 1233-007-1200 | ND |
| 2018-07-11 | 9590-007-1200 | ND |
| 2019-07-10 | 1233-006-1200 | ND |
| 2019-07-10 | 1233-007-0830 | ND |