BENTAZONE

Common name:Bentazone

Chemical Name:

3-Isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide

3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide

Other names:

Basagran(Brand name of BASF SE)

Molecular formulae: C10H12N2O3S Chemical Structure:

Physical and Chemical Properties

Molecular weight:240.3; Physical form: Colourless crystals.Density:1.41 (20℃); Composition:96% pure. Melting point:139.4-141 ℃; Vapour pressure:0.17 (20℃); Partition coefficient(n-octanol and water): logP = 0.77 ( 5), -0.46 ( 7), -0.55 ( 9); pKa:3.3

(24 °C); Solubility: In water 570 /l ( 7, 20 ℃). In acetone 1387, methanol 1061, ethyl acetate 582, dichloromethane 206(all in g/l, 20 ℃).; Stability: Very resistant to hydrolysis in both acidic and alkaline media. Decomposed by sunlight.

Purity: 95%, 98%

Uses:It is considered safe for use on soybean, peanut, wheat, rice, corn, beans, kidney beans, peas, sugar cane, onion, sweet potato, potato, tea plantations, flax, alfalfa, mint, astragalus membranaceus, Perilla, lawn.

Mode of actions:

Biochemistry Photosynthetic electron transport inhibitor at the photosystem II receptor site. Mode of action Selective contact herbicide, absorbed mainly by the foliage, with very little translocation, but also absorbed by the roots, with translocation acropetally in the xylem. Uses a contact herbicide controlling Anthemis, Chamomilla and Matricaria spp., Chrysanthemum segetum, Galium aparine, Lapsana communis and Stellaria media in winter and spring cereals.

Bentazone is a selective herbicide as it only damages plants unable to metabolize the chemical. Bentazone is usually applied aerially or through contact spraying on food crops to control the spread of weeds occurring amongst food crops. Herbicides containing

Bentazone should be kept away from high heat as it will release toxic sulfur and nitrogen fumes.

Toxicology:

Oral: Acute oral LD50 for rats 1000mg/kg, dogs 500 mg/kg, rabbits 750 mg/kg, cats 500 mg/kg

Percutaneous: Acute percutaneous LD50 for rats 2500 mg/kg Moderately irritating to skin and eyes (rabbits)

Inhalation: LC 50 (4 h) for rats 5.1mg/L air Environmental Profile

Algae: for green algae (Ankistrodesmus) LC50:47.3 g/kg

Bees: Not toxic to bees; Birds: Acute oral LD50 for bobwhite quail 1140g/kg. for bobwhite quail and mallard ducks 5000

Daphnia: LC 50 (48 h) 125g /l.

Fish:LC50 (96 h) for rainbow trout and bluegill sunfish 100g/l. Worms: LC50 (14 d) 1000g /l.

Ecotoxicology

Environmental fate:

Animals: Metabolism studies in three different species showed that Bentazone was only poorly metabolised, the parent compound being the predominant product. Only small amounts of hydroxylated Bentazone metabolites could be detected. No conjugated products were for Soil: In soil, short-lived hydroxy compounds are first formed, which rapidly undergo further degradation. In sunlight, Bentazone undergoes rapid degradation, ultimate Plant:In plants, rapidly metabolised to derivatives of anthranilic acid, the principal metabolites being the 6- and 8-hydroxy derivatives, which are conjugated to sugars, forming glycosides

Transportation Information:

Signal Word: CAUTION; Hazard Class:III(Slightly hazardous) UN NO. 3077

Other products:

Straight Formulated Products:

Bentazone 480g/L SL; Bentazone 80% SP;

Mixtures:

Fomesafen +Bentazone SL; Quizalofop-p-ethyl +Bentazone EC; MCPA+ Bentazone SP

Thifensulfuron-methyl+bentazone+flumetsulam;Bentazone+carfentrazone-ethyl;Bentazon e+Quinclorac;Acifluorfen+Bentazone; Imazamox+Bentazone Soluble concentrate (sodium salt), soluble granules.

Premix Parters: clomazone; cumyluron thenylchlor.