Bottle of Semazine 4L Herbicide A container of Simazine liquid herbicide.

Simazine is an herbicide used to target broad-leafed weeds in crops like corn, oranges, and asparagus. It’s a triazine-derived herbicide, making it a close cousin to atrazine. Simazine kills plants by inhibiting photosynthesis, their ability to get energy from sunlight.

Simazine gets into local drinking water supplies by rain and irrigation runoff from soil. Once introduced, the chemical can stay active for 2 to 7 months.

Because it is toxic to humans, Simazine has been banned by the European Union. Short-term exposure can alter the blood and symptoms include mysterious weight loss. Symptoms of long-term exposure include:

  • Tremors
  • Cancer
  • Gene mutation
  • Testicular damage
  • Liver damage
  • Kidney damage
  • Thyroid damage

It’s possible for refrigerator water filters to remove simazine from drinking water, but it’s hard to determine how much. The best first step toward checking your water for simazine is by using the WaterSafe All-In One Home Drinking Water Test Kit.