Know Your Environment. Protect Your Health.

Simazine

Guadalupe Blanco River Authority

Simazine is a hormone-disrupting herbicide related to atrazine. It affects the male and female reproductive systems. In studies of laboratory animals, simazine increases blood levels of estrogen, decreases prolactin and progesterone, and causes mammary and ovarian tumors.

 

12

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND10ND
2019ND10ND
2020ND10ND
2021ND10ND
2022ND40ND
2023ND40ND

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.1 ppb

The EWG Health Guideline of 0.1 ppb for simazine was defined by EWG based on epidemiological studies of human exposure to atrazine in drinking water. This health guideline protects against harm to the developing fetus, harm to the reproductive system and hormone disruption.

EPA Maximum Contaminant
Level (MCL): 4 ppb

The legal limit for simazine, established in 1992, was based on toxicity studies in laboratory animals conducted in the 1980s. This limit does not fully protect against harm to the reproductive system, harm to the developing fetus, and hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2018-03-01AE16455ND
2019-02-25AE56116ND
2020-03-16AF03078ND
2021-03-22AF47903ND
2022-02-14AF84742ND
2022-04-26AF94678ND
2022-08-18AG10108ND
2022-12-29AG23208ND
2023-02-15AG29147ND
2023-04-18AG37203ND
2023-07-24AG49877ND
2023-10-18AG60308ND