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| | Metribuzin Basic information |
| | Metribuzin Chemical Properties |
| Melting point | 125°C | | Boiling point | 132 °C(Press: 0.02 Torr) | | density | 1.28 | | refractive index | 1.6390 (estimate) | | Fp | 2 °C | | storage temp. | APPROX 4°C
| | solubility | DMSO (Slightly), Methanol (Slightly) | | pka | -0.16±0.20(Predicted) | | form | Solid | | color | White | | Odor | mild odor | | Water Solubility | Slightly soluble | | BRN | 746650 | | Exposure limits | NIOSH REL: 5 mg/m3; ACGIH TLV: TWA 5 mg/m3. | | NIST Chemistry Reference | Metribuzin(21087-64-9) | | EPA Substance Registry System | Metribuzin (21087-64-9) |
| | Metribuzin Usage And Synthesis |
| Chemical Properties | White Solid | | Chemical Properties | Metribuzin is a colorless crystalline solid.
Commercial product may be a flammable solution. Mild,
sulfurous odor. | | Uses | Selective herbicide used for preemergence broad-leaved weed control in potatoes,
tomatoes, lucerne, raspberry and sugarcane, and postemergence weed control in beets.
Also used for selective control of annual grasses. | | Uses | Herbicide. | | Uses | Metribuzin is an is an aminotriazinone herbicide used in agriculture for both pre- and post-emergence in crops including soy bean, potatoes, tomatoes and sugar cane. Metribuzin acts by inhibiting phot
osynthesis by disrupting photosystem II. | | Definition | ChEBI: A member of the class of 1,2,4-triazines that is 1,2,4-triazin-5(4H)-one substituted by an amino group at position 4, tert-butyl group at position 6 and a methylsulfanyl group at position 3. | | General Description | Colorless crystalline solid. Used as an herbicide. Non corrosive. | | Reactivity Profile | A triazine derivative. Amines are chemical bases. They neutralize acids to form salts plus water. These acid-base reactions are exothermic. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides. | | Hazard | Toxic material. Liver damage and hemato-logic effects. Questionable carcinogen. | | Health Hazard | Low to moderate acute toxicity; single highdose may cause depression of central nervoussystem; repeated high doses affect thyroidand stimulate the metabolizing liver enzymes(ACGIH) 1986; excretes out rapidly; noirritant action on skin or eye; no teratogenic,mutagenic or carcinogenic effect observed inanimal studies.
LD50 oral (rat): 1100 mg/kg
LD50 oral (mouse): 698 mg/kg
LD50 oral (guinea pig): 250 mg/kg
LD50 skin (rat): 2000 mg/kg. | | Agricultural Uses | Herbicide: Metribuzin is a selective triazine herbicide which
inhibits photosynthesis of susceptible plant species. It is
used for control of annual grasses and numerous broadleaf
weeds in asparagus, potatoes, lucerne, peas, lentils, soya
beans, sugar cane, sainfoin, pineapples and cereals. It is
applied to fallow lands. Metribuzin is available as liquid
suspension, water dispersible granular, and dry flowable
formulations. | | Trade name | AUTHORITY®; AXIOM® Metribuzin;
BAY 61597®; BAY DIC 1468®; BAYER 6159H®;
BAYER 6443H®; BAYER 94337®; BOUNDARY®;
CANOPY®; CONQUEST®; DIC 1468®; DOMAIN®;
LEXONE®; LEXONEEX®; PREVIEW®[C];
PYTHON®; SENCOR®; SENCORAL®; SENCOREX®;
SENCORER®; VAPCOR® | | Safety Profile | Poison by ingestion and
intraperitoneal routes. Low toxicity by skin
contact. When heated to decomposition it
emits very toxic fumes of NOx and SOx. | | Potential Exposure | A potential danger to those involved
in manufacture, formulation, and application of this
herbicide. A laboratory chemical. Used to make other
chemicals. | | Environmental Fate | Soil. In soils, metribuzin undergoes deamination and further degradation forming water
soluble conjugates (Hartley and Kidd, 1987). Metribuzin degrades rapidly in soil (Kempson-
Jones and Hance, 1979; LaFleur, 1980). The half-lives in soil ranged from 4 to 9
weeks at 22°C and 60% moisture content to 9 to 11 weeks at 10°C and 10% moisture
content. The highest half-life reported ranged from 15 to 43 weeks in a soil having 60%
moisture content maintained at 10°C (Kempson-Jones and Hance, 1979).
The dissipation rates (day–1) for metribuzin on Hillsdale silty loam, Cecil silty loam,
Regina heavy clay, Melfort clay loam and White City silt loam were 0.013-0.017, 0.055-
0.131, >0.017, >0.0016 and >0.023, respectively.
Groundwater. According to the U.S. EPA (1986) metribuzin has a high potential to
leach to groundwater.
Plant. Metribuzin is metabolized in soybean plants to a deaminated diketo derivative
which is nonphytoxic (Duke et al., 1991).
Photolytic. The simulated sunlight (l >230 nm) photolysis as a thin film on silica gel
or sand yielded 6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5-(4H)-one and two
additional photoproducts. In both of the unnamed photoproducts, the methylthio group in
the parent compound is replaced by oxygen and one of the compounds also underwent
N-deamination (Bartl and Korte, 1975).
Chemical/Physical. Emits toxic fumes of nitrogen and sulfur oxides when heated to
decomposition (Lewis, 1990). | | Shipping | UN2763 Triazine pesticides, solid, toxic, Hazard
Class: 6.1; Labels: 6.1-Poisonous materials. | | Incompatibilities | Liquid is 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. | | Waste Disposal | 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. Use a licensed professional waste disposal service
to dispose of this material. Dissolve or mix the material with
a combustible solvent and burn in a chemical incinerator
equipped with an afterburner and scrubber. All federal, state,
and local environmental regulations must be observed. |
| | Metribuzin Preparation Products And Raw materials |
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