The compound is used to control broad-leaved weeds and annual grasses.

Simazine may be prepared from cyanuric chloride and a concentrated solution of ethyl amine (at least 50 percent by number) in water.

Simazine is an off-white crystalline compound which is sparingly soluble in water.

[2] Like atrazine, a related triazine herbicide, it acts by inhibiting photosynthesis.

It remains active in the soil for two to seven months or longer after application.