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EWG's Tap Water Database — 2021 UPDATE

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2,4-D

Castle Rock

2,4-D (2,4-dichlorophenoxyacetic acid) is a herbicide that can be applied directly to GMO corn and soy plants engineered to withstand this toxic chemical. Americans' exposures to 2,4-D from food and drinking water will likely increase in years to come as farmers plant more of these GMO crops. Read More.

2,4-D is an endocrine disruptor that interferes with thyroid hormones. The International Agency for Research on Cancer classifies 2,4-D as possibly carcinogenic to humans. In occupational studies, farmers exposed to 2,4-D tended to have higher incidences of damaged and malformed sperm. Laboratory animals exposed to 2,4-D during gestation are born underdeveloped and are more likely to have birth defects.

 

39

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND70ND
2015ND10ND
2016ND50ND
2017ND100ND
2018ND80ND
2019ND80ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 20 ppb

The EWG Health Guideline of 20 ppb for 2,4-D 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) 70 ppb

The legal limit for 2,4-D, established in 1991, was based on toxicity studies in laboratory animals conducted in the 1980s. This limit may not fully protect against harm to the nervous system, harm to the thyroid, and hormone disruption.

ppb = parts per billion

All test results

Date Result
2014-02-04ND
2014-04-29ND
2014-07-21ND
2014-07-22ND
2014-11-19ND
2014-12-04ND
2014-12-04ND
2015-08-05ND
2016-02-23ND
2016-02-24ND
2016-05-23ND
2016-06-27ND
2016-11-14ND
2017-02-21ND
2017-02-21ND
2017-03-22ND
2017-04-18ND
2017-04-18ND
2017-05-16ND
2017-06-21ND
2017-07-17ND
2017-07-17ND
2017-10-18ND
2018-03-20ND
2018-03-20ND
2018-05-21ND
2018-08-30ND
2018-09-13ND
2018-11-16ND
2018-12-12ND
2018-12-12ND
2019-02-07ND
2019-04-17ND
2019-09-16ND
2019-09-16ND
2019-11-05ND
2019-11-25ND
2019-12-11ND
2019-12-11ND