Know Your Environment. Protect Your Health.

Simazine

Harris County Municipal Utility District 344

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.

 

7

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.0192 ppb396ND - 0.140 ppb
20190.0700 ppb110.0700 ppb
2020ND30ND
2021ND10ND
20220.200 ppb110.200 ppb
2023ND10ND

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
2019-02-11AE539150.0700 ppb
2020-03-26AF04795ND
2020-05-11AF10491ND
2020-09-03AF26553ND
2021-03-04AF45497ND
2022-02-07AF835280.200 ppb
2023-03-09AG32492ND