ГЛИФОСАТ химические свойства, назначение, производство
Описание
Glyphosate (N-(phosphonomethyl)glycine; 1071-83-6) is the
active ingredient in several commercial herbicides for nonselective
weed control. Glyphosate herbicides are among the
world’s most widely used herbicides. Roundup?, containing
the active ingredient glyphosate, was developed and introduced
by Monsanto Company in 1974. Other formulations include
WeatherMax, UltraMAX, Buccaneer, Razor Pro, Rodeo, and
AquaMaster?. Some crops such as soybeans and cotton have
been genetically engineered to be resistant to glyphosate
(Roundup Ready), allowing farmers to use glyphosate as
a postemergence herbicide. The United States Environmental
Protection Agency (EPA) considers glyphosate to be relatively
low in toxicity compared to organochlorine and organophosphate
pesticides.
Химические свойства
Glyphosate is a broad-spectrum, non-selective systemic herbicide. It is a colorless crystal at room temperature and is soluble in acetone, ethanol, xylene, and water. Glyphosate is used for the control of annual and perennial plants, including grasses, sedges, broadleaved weeds, and woody plants. It can be used on non-cropland as well as on many varieties of crops. Glyphosate itself is an acid, but it is commonly used in salt form, most commonly isopropylamine salt. It may also be available in acidic or trimethylsulfonium salt forms. It is generally distributed as water-soluble concentrates and powders. Glyphosate is a GUP.
Использование
Glyphosate is the active ingredient in several commercial
herbicides. It is a broad-spectrum systemic herbicide for various
types of weeds, grasses (Poaceae), and woody plants.
Общее описание
Odorless white powder. Decomposition begins at approximately 419°F (darkens). pH (1% solution in water) 2.5.
Профиль реактивности
Glyphosate may react with galvanized steel or unlined steel (except stainless steel) containers to produce hydrogen gas which may form a highly combustible or explosive gas mixture. Glyphosate can react with caustic (basic) materials to liberate heat. Glyphosate is corrosive to iron.
Угроза здоровью
Glyphosate is practically non-toxic if ingested, with a reported acute oral LD50 of 5600 mg/kg in the rat. The toxicities of the technical acid (glyphosate) and the formulated product (Roundup) are nearly the same. Laboratory animals, such as rats, dogs, mice, and rabbits, exposed to glyphosate for 2 years did not indicate any kind of adverse health effects.
Пожароопасность
Flash point data for Glyphosate are not available; however, Glyphosate is probably combustible.
Фармаколо?гия
Glyphosate is the only known inhibitor of the biosynthesis
of aromatic acids that has been commercialized as a
successful herbicide (1). Glyphosate acts as a competitive
inhibitor of phosphoenolpyruvate, the natural substrate of
the enzyme 5-enolpyruvyl-shikimate-3-phosphate (EPSP)
synthase, and causes amassive accumulation of shikimate
in treated plant tissue (1).
Glyphosate is a nonselective herbicide, and it has
been characterized as a low-risk herbicide for the
evolution of herbicide resistance. A few weed species
are somewhat tolerant to glyphosate, probably due
to uptake or translocation mechanisms, but no plant
species has sufficient resistance to glyphosate to allow its use directly on the crop as a selective herbicide.
The complicated procedure used to genetically engineer
the commercialized glyphosate-tolerant crops (31) would
suggest that the evolution of glyphosate-resistant weeds
will be a very slow process and that the level of resistance
from field selection will be relatively low.
Профиль безопасности
Poison by intraperitoneal route. Moderately toxic by ingestion. Human systemic effects: arrhythmias, blood pressure lowering, body temperature increase, change in heart rate, convulsions, darrhea, fibrosing alveolitis, fibrosis, hypermoultty, respiratory depression, respiratory stimulation. Used as an herbicide. When heated to decomposition it emits very toxic fumes of NOx and POx.
Возможный контакт
A potential danger to those involved
in the manufacture, formulation, and application of this
nonselective and nonresidual pre-emergence organophos phate herbicide. Has wide residential use in the United
States for the control of weeds.
Метаболический путь
The photolytic degradation of glyphosate results in the
formation of glycine, (aminomethyl)phosphonic acid
(AMPA), and NH3. Glyphosate undergoes
nitrogen ? carbon cleavage on reaction with m-
chloroperoxybenzoic acid, leading ultimately to many
of the same products formed on their metabolism and
environmental degradation. It is suggested that
insoluble complexes of glyphosate with iron(III),
copper(II), calcium, and magnesium ions are formed at
near-neutral pH, a mechanism of which is the
inactivation of glyphosate in contaminated
groundwater.268 The bacterium degrades high levels of
glyphosate, primarily by converting to AMPA.
Appreciable uptake of glyphosate is observed with
seedlings and leaves and to a lesser extent with
culture cells in the form of non-metabolized
glyphosate, with AMPA as the only detectable
metabolite.
Метаболизм
In soils, glyphosate is rapidly mineralized within 1
to 2 weeks, and degradation occurs under aerobic and
anaerobic conditions (79). The C?P bond is relatively
resistant to chemical degradation, but several bacteria,
e.g., Arthrobacter (80), Pseudomonas (81), various members
of the Rhizobiaceae family (82), and certain fungi (83),
have been shown to metabolize glyphosate.
Перевозки
UN3077 Environmentally hazardous substances,
solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous haz ardous material, Technical Name Required.
Несовместимости
Organophosphates are susceptible to for mation of highly toxic and flammable phosphine gas in the
presence of strong reducing agents such as hydrides. Partial
oxidation by oxidizing agents may result in the release of
toxic phosphorus oxides. 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, dithio carbamates, isocyanates, mercaptans, nitrides, sulfides
(releasing heat, toxic, and possibly flammable gases), thio sulfates, and dithionites (releasing hydrogen sulfate and
oxides of sulfur). Solutions are corrosive to iron, unlined
steel, and galvanized steel, forming a highly combustible or
explosive gas mixture. Do not store glyphosate in contain ers made from these materials.
ГЛИФОСАТ препаратная продукция и сырье
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