Picloram

Описание

Picloram is a colourless crystal. It is very soluble in acetone, ethanol, benzene, and dichloromethane. It is a systemic herbicide used for general woody plant control, sold under the trade names Tordon and Grazon. It also controls a wide range of broad-leaved weeds, but most grasses are resistant. It is used in formulations with other herbicides such as bromoxynil, diuron, 2,4-D, MCPA, triclorpyr, and atrazine. It is also compatible with fertilisers. Picloram, in the pyridine family of compounds, is a systemic herbicide used for control of woody plants and a wide range of broad-leaved weeds. Most grasses are resistant to picloram, so it is used in range management programs. Picloram is formulated either as an acid (technical product), a potassium or triisopropanolamine salt, or an isooctyl ester, and is available as either soluble concentrates, pellets, or granular formulations. The materials in this document refer to the technical acid form unless otherwise indicated. Picloram is stable under acidic, neutral and basic conditions. Picloram is formulated either as an acid (technical product), a potassium or triisopropanolamine salt, or an isooctyl ester, and is available as either soluble concentrates, pellets, or granular formulations and related manufacturing impurities.

Химические свойства

Picloram is a colorless powder. Chlorine odor.

Использование

Picloram is a dicot-selective, persistent herbicide and in salt form is used to control a variety of annual weeds on crops, perennial broadleaved herbs, and woody species in combination with 2,4-D or 2,4,5-T. It can persist in an active form in the soil from several months to years, and can also be released from the roots of treated plants into the soil, where other nontarget species may take it up and die. Picloram is of great use in the management of unwanted vegetation in rangeland, grass pastures, and forestry as well as non-cropland and rightsof- way sites, such as around industrial and military installations, roads, railways, airports, under power lines, and along pipelines. Additional uses in some countries include in rice, sugarcane, cereals, and oilseed rape.

Общее описание

Fine beige crystals or white powder. Odor of chlorine.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

Picloram may be sensitive to prolonged exposure to light. Aqueous solutions may be decomposed by light. Picloram is incompatible with strong oxidizing agents, strong acids, acid chlorides and acid anhydrides.

Угроза здоровью

The toxic effects from ingestion or inhalation of dusts of picloram in test animals were mild. The acute oral LD50 values inrats and rabbits are 2900 and 2000 mg/kg,respectively. Maternal toxicity in rats wasobserved at a dose level of 750 mg/kg/day.Oral administration of picloram in rats andmice caused tumors in thyroid and liver.

Пожароопасность

Flash point data for Picloram are not available; however, Picloram is probably combustible.

Сельскохозяйственное использование

Herbicide: Picloram is a systemic herbicide used for control of woody plants and a wide range of broad-leaved weeds along roads, power lines and long right-of-ways. Most grasses are resistant to picloram, so it is used in range management programs to control noxious weeds and brush. It is used to prepare sites for tree planting. Picloram is formulated either as an acid (technical product), a potassium or triisopropanolamine salt, or an isooctyl ester, and is available as either soluble concentrates, pellets, or granular formulations. During the Vietnam war, a herbicide named Agent White was used to control vegetation. It was a mixture of 2,4-D, triisopropanolamine salt and picloram. A U.S. EPA restricted Use Pesticide (RUP).

Торговое название

ACCESS®; AMDON®; AMDON GRAZON®; BOROLIN®; GRAZON® Picloram; K-PIN®; PATHWAY®; TORDON®[C]; TORDON® 101 MIXTURE; TORDON® 10 K; TORDON® 22 K

Профиль безопасности

Moderately toxic by ingestion. Questionable carcinogen with experimental carcinogenic, neoplas tigenic, tumorigenic, and teratogenic data. An experimental teratogen. Mutation data reported. When heated to decomposition it emits very toxic fumes of Cland NOx.

Возможный контакт

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

Метаболизм

Chemical. Picloram is generally stable to hydrolytic degradation but will decompose in hot, concentrated alkali solutions. It undergoes photodecomposition when irradiated with UV light and, to a lesser extent, with sunlight. Degradation via photolysis is thought to primarily involve cleavage of the ring structure and liberation of substituent chlorine atoms producing oxamic acid and 3-oxo-β-alanine. Decarboxylation is not thought to be a major pathway in photolytic degradation.
Plant. Hall et al. (16) have shown that in rapeseed plants (Brassica spp.) >25% of picloram is metabolized 24 hours after treatment.
Soil. There is only limited microbial degradation in the soil. If picloram remains on the soil surface, it may undergo photolysis.

Перевозки

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

Несовместимости

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. Compounds of the carboxyl group react with all bases, both inorganic and organic (i.e., amines) releasing substantial heat, water and a salt that may be harmful. Incompatible with arsenic compounds (releases hydrogen cyanide gas), diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides (releasing heat, toxic and possibly flammable gases), thiosulfates and dithionites (releasing hydrogen sulfate and oxides of sulfur). This material is acidic. Reacts with hot concentrated alkali (hydrolyzes), strong bases. May attack metals.

Утилизация отходов

This chlorinated brush killer is usually formulated with 2,4-D and the disposal problems are similar. Incineration @ 1000C for 2 seconds is required for thermal decomposition. Alternatively, the free acid can be precipitated from its solutions by addition of a mineral acid. The concentrated acid can then be incinerated and the dilute residual solution disposed in an area where several years’ persistence in the soil can be tolerated.