БЕНТАЗОН

Описание

Bentazon is unique under these herbicides because it is the only compound that bears a sulfonyl group. A puzzle that is not solved yet is that bentazone is an excellent herbicide but has a very low pI50-value.

Химические свойства

Bentazon is a colorless to white crystalline powder.

Использование

Herbicide.

Определение

ChEBI: A benzothiadiazine that is 1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide substituted by an isopropyl group at position 3.

Сельскохозяйственное использование

Selective post-emergent herbicide: A post-emergence herbicide used to control broadleaf weeds in crops such as beans, corn, mint, soybeans, rice, and peanuts. All products formerly marketed in the U.S. contain the sodium salt of bentazon as the active ingredient, referred to as sodium bentazon. Also used in selective post-emergent control of broadlelaf weeds and sedges in alfalfa, asparagus, cereals, clover, digitalis, dry peas, flax, garlic, grasses, green lima beans, mint, onions, potatoes, snap beans for seed, sorghum, soybeans and sugarcane. Not currently registered in the U.S. It is reported to be used in most European countries.

Торговое название

ASAGIO®; BAS 351-H®; BASAGRAN®; BENDIOXIDE®; BENTA®; BLAST®; ENTRY®; LADDOK®; LEADER®; PLEDGE®; STORM®

Профиль безопасности

Moderately toxic by ingestion and skin contact. An experimental teratogen. Other experimental reproductive effects. When heated to decomposition it emits very toxic fumes of SO, and NOx.

Возможный контакт

A potential danger to those involved in the manufacture, formulation or application of this selective postemergent thiadiazine herbicide.

Экологическая судьба

Soil. Under aerobic conditions, bentazone was reported to degrade to 6- and 8-hydrox ybentazone compounds. In addition, anthranilic acid and isopropylamide were reported as soil hydrolysis products (Otto et al., 1978). Persistence in soil is less than 6 weeks (Hartley and Kidd, 1987). Bentazone is readily adsorbed onto organic carbon and therefore, is not expected to leach to groundwater (Abernathy and Wax, 1973). The dissipation half life of bentazone in field soil is 5 days (Ross et al., 1989).
Plant. Undergoes hydroxylation of the aromatic ring and subsequent conju-gation in plants (Otto et al., 1978; Hartley and Kidd, 1987) forming 6- and 8-hydroxybentazone compounds (Otto et al., 1978). The half-life in and/or on plants is 2–3 days (
Photolytic. Humburg et al. (1989) reported that 30% degradation of bentazone on glass plates occurred when exposed to UV light (λ = 200–400 nm); however, no photoproduct(s) were reported. The natural sunlight and simulated sunlight irradiation of
Chiron et al. (1995) investigated the photodegradation of bentazone (20 μg/L) in distilled water and Ebro River water using an xenon arc irradiation. In distilled water, bentazone completely disappeared after 16 hours of irradiation. Photodegradation appeared to follow pseudo-first-order kinetics with a half-life of about 2.5 hours. The presence of humic substances (4 mg/L) increased the rate of photodegradation and the disappearance of bentazone was achieved in 8 hours. No significant breakdown photoproducts were identified.

Метаболический путь

14C-Bentazon degrades in soils under conventional tillage and no-tillage (3-18 years) with varying histories of bentazon application. The half-life for bentazon degradation ranges from 4.6 to 49.5 days; half-lives for some no-tillage soils with the longest histories of application are lower than those of conventional tillage soils. Half-lives for soils with no bentazon history are 3-11 times higher than the half- lives of those previously exposed to bentazon. N- Methylbentazon is the most consistently observed metabolite. The other metabolites identified in soils result from hydroxylation on the phenyl ring and the cleavage of the benzothiadiazine ring, yielding 6- and 8-hydroxybentazons and anthranilic acid via 2-amino-N-isopropylbenzamide.

Перевозки

UN2588 Pesticides, solid, toxic, Hazard Class: 6.1; Labels: 6.1—Poisonous materials, Technical Name Required.

Несовместимости

Keep away from flammable materials, heat and flame. Risk of fire and explosion if formulations contain flammable/explosive solvents.

Утилизация отходов

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.