Metamitron

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Chemical Identification | General Product Information | Physical & Safety Data

Chemical Identification

Common Name

Metamitron

中文通用名

苯嗪草酮

IUPAC

4-amino-4,5-dihydro-3-methyl-6-phenyl-1,2,4-triazin-5-one; 4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one

CAS

4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one

CAS No.

41394-05-2

Molecular Formula

C₁₀H₁₀N₄O

Molecular Structure

General Product Information

Category

Herbicides > Triazinone herbicides

Activity

The mode of action of metamitron is to disrupt photosystem II, inhibiting electron transport. It is applied as a foliar spray, and is absorbed effectively through the leaf surface and the roots. Once absorbed it is translocated acropetally to the leaves of the target plants.

CropUse

Being a selective herbicide, metamitron can be used on pre-emergance or post-emergance weeds. Target plants are weeds of fodder beet, mangels, red beets and sugar beets. These include grasses and broad-leaved weeds.

Formulation

WG = Water dispersible granules
WP = Wettable powder

Premix

Premix Parters: desmedipham, ethofumesate and phenmedipham

Physical & Safety Data

Physical Properties

Molecular weight:202.2; Physical form:Yellowish, odourless crystals. Density:1.35 g/cm3 (22.5 °C); Melting point:166.9 °C; Vapour pressure:8.6 × 10-4 (20 °C); 2 × 10-3 (25 °C); Henry constant:1 × 10-7 Pa m3 mol-1 (20 °C, ); Partition coefficient(n-octanol and water):logP = 0.83; Solubility:In water 1.7 g/l (20 °C). In dichloromethane 30-50, cyclohexanone 10-50, isopropanol 5.7, toluene 2.8, hexane <0.1, methanol 23, ethanol 1.1, chloroform 29 (all in g/l, 20 °C).; Stability:Very stable in acidic media; decomposed by strong alkalis ( >10); 50 (22 °C) 410 d ( 4), 740 h ( 7), 230 h ( 9). Photodecomposition on soil surfaces i;

Toxicology

Oral:Acute oral 50 for rats c. 1200, mice c. 650, dogs >1000 /. Percutaneous:Acute percutaneous 50 for rats >4000 /kg. No irritation of skin and eyes (rabbits). Inhalation:50 (4 h) for rats >0.33 /l air (aerosol). Phytotoxicity:High selectivity in sugar and fodder beet.

Environmental Profile

Ecotoxicology:
Algae:rC₅₀ for Scenedesmus subspicatus 0.22 /l.Bees:Not toxic to bees.Birds:Acute oral 50 for Japanese quail 1875-1930 /.Daphnia:50 (48 h) 101.7-206 /l.Fish:50 (96 h) for golden orfe 443, rainbow trout 326 /l.Worms:50 for Eisenia foetida >1000 / dry soil.

Environmental fate:
Animals:In mammals, following oral administration, elimination occurs within 48 hours, approximately equally in the urine and faeces (c. 98%).Soil:In soil, metamitron is degraded very rapidly. Leaching behaviour can be classified as medium mobile; no leaching into groundwater occurred. Rapid photodecomposition on soil surfaces and in aqueous solution is an important process for the degradation of mePlant:In sugar beet, the principal metabolite is 3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one.

Transport Information

Signal Word:CAUTION; Hazard Class:III(Slightly hazardous)