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| | diquat dichloride Basic information |
| | diquat dichloride Chemical Properties |
| | diquat dichloride Usage And Synthesis |
| Description | Diquat dibromide is a contact desiccant and herbicide. It is highly soluble in water, has a low risk of leaching to groundwater and is volatile. It is very persistent in soil but rapidly degrades in aquatic systems. It is moderately toxic to mammals and is a known irritant but no other significant human health issues have been identified. It is moderately toxic to birds, most aquatic organisms, honeybees and earthworms. | | Chemical Properties | Paraquat is a yellow solid with a faint,
ammonia-like odor. | | Production Methods | Diquat dichloride was manufactured through a well-established quaternisation process built around the bipyridyl core. Producers first formed the parent diquat skeleton by coupling two pyridine derivatives under conditions that generated the 4,4′ bipyridyl framework, followed by purification to remove by-products typical of bipyridyl chemistry. This intermediate was then subjected to controlled alkylation with ethylene dibromide or a comparable dihaloalkane, which simultaneously quaternised both nitrogen atoms and closed the ethylene bridge to form the characteristic diquat dication. A final metathesis or neutralisation step introduced chloride as the counter-ion, yielding diquat dichloride as a stable, crystalline technical material suitable for formulation. | | Mechanism of action | Non-selective, contact absorbed through foliage, some desiccant action. Photosystem I (electron transport) inhibitor. | | Potential Exposure | Those engaged in manufacture,
formulation and application of this herbicide. Classified
for restricted use: limited to use by a certified applicator, or
those under applicator’s direct supervision. | | Shipping | UN2781 Bipyridilium pesticide, solid, toxic,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials. | | Incompatibilities | Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,
bromine, fluorine, etc.); contact may cause fires or explosions.
Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides (hydrolysis), alkylarylsulfonate
wetting agents. Corrosive to metals. Decomposes
in presence of ultraviolet (UV) light. Decomposes in heat
(see physical properties, above) and in the presence of UV
light, producing nitrogen oxides, hydrogen chloride. | | Waste Disposal | Paraquat is rapidly inactivated
in soil. It is also inactivated by anionic surfactants.
Therefore an effective and environmentally safe disposal
method would be to mix the product with ordinary household
detergent and bury the mixture in clay soil. In
accordance with 40CFR165, follow recommendations for
the disposal of pesticides and pesticide containers. Must be
disposed properly by following package label directions or
by contacting your local or federal environmental control
agency, or by contacting your regional EPA office. Consult
with environmental regulatory agencies for guidance on
acceptable disposal practices. Generators of waste containing
this contaminant (≥100 kg/mo) must conform with
EPA regulations governing storage, transportation, treatment,
and waste disposal. | | Pesticide Type | Herbicide |
| | diquat dichloride Preparation Products And Raw materials |
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