Simazine is an herbicide of the triazine class. The compound is used to control broad-leaved weeds and annual grasses.
Simazine’s HRAC classification is Group C1, Group C (global, Aus), Group 5 (numeric), as it inhibits photosynthesis at photosystem II.[1]
Preparation
Simazine may be prepared from cyanuric chloride and a concentrated solution of ethyl amine (at least 50 percent by number) in water.[2] The reaction is highly exothermic and is therefore best carried out below 10 °C.
Cyanuric chloride decomposes at high temperatures into hydrogen chloride and hydrogen cyanide, both of which are highly toxic by inhalation.
Properties and uses
Simazine is an off-white crystalline compound which is sparingly soluble in water. It is a member of the triazine-derivative herbicides, and was widely used as a residual non-selective herbicide, but is now banned in European Union states.[3] 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.
See also
References
- ^ “Classification of Herbicides According to Site of Action”. Retrieved 19 July 2025.
- ^ “Simazine: Methods of Manufacturing”. PubChem.
- ^ 2004/247/EC: Commission Decision of 10 March 2004 concerning the non-inclusion of simazine in Annex I to Council Directive 91/414/EEC and the withdrawal of authorisations for plant protection products containing this active substance
External links
- Simazine, Extoxnet PIP