IDENTIFICATION
Common name: Glyphosate
Other name: glyphosate (BSI, E-ISO, (m) F-ISO, ANSI, WSSA, JMAF)
Iupac name: N-(phosphonomethyl)gtycine
Chemical abstracts name: N-(phosphonomethyl)glycine
Type: Herbicide
CAS RN: [1071-83-6]
M.F.: C3H8NO5P
Mol Wt: 169.1
PHYSICAL CHEMISTRY
Form (appearance): Colourless crystals.
Composition:: Tech. is ≥95% pure. Zwitterion structure
M.P.: 189.5±0.5℃
B.P.: Decomp. >200℃
V.P.: 1.31 × 10-2 mPa (25℃)
F.P.: Not flammable
S.G.: 1.705 (20℃)
Solubility.: In water 11.6 g/l (25℃). Insoluble in common organic solvents, e.g. acetone, ethanol and xylene. The alkali metal and amine salts are readily soluble in water.
Stability: Glyphosate and all its salts are non-volatile, do not phot0chemically degrade and are stable in air. Glyphosate is stable to hydrolysis at pH 3, 6 and 9 (5-35℃).
Henry: <2.1 × 10-7 Pa m3 mol-1
KowlogP: < -3.2 (pH 2-5, 20℃) (OECD 107; EEC AS)
Pka: 5.77±0.03, 2.18±0.02 (20±2℃) (OECD 112)
APPLICATION
Formulation types: SG; SL.
Biochemistry: Inhibits 5 enolpyruvytshikimate 3 phosphate synthase (EPSPS), an enzyme of the aromatic acid biosynthetic pathway. This prevents synthesis of essential aromatic amino acids needed for protein biosynthesis.
Mode of action: Non-selective systemic herbicide, absorbed by the foliage, with rapid transtocation throughout the plant, Inactivated on contact with soil.
Uses: Control of annual and perennial grasses and broad leaved weeds, pre harvest, post-planting/pre-emergence and in stubble, in cereals, peas, beans, oilseed rape, flax and mustard, at c. 1.5- 2 kg/ha; as a directed spray in vines and olives, at c. 4.3 kg/ha; in orchards, pasture, forestry and industrial weed control, at c. 4.3 kg/ha. As an aquatic herbicide, at c. 2 kg/ha.
Compatibility: Mixing with other herbicides may reduce the activity of glyphosate.
MAMMALIAN TOXICOLOGY
Oral: Acute oral LD50 for rats 5600, mice 11300, goats 3530 mg/kg. Skin and eye Acute percutaneous LD50 for rabbits >5000 mg/kg. Eye irritant; non-irritating to skin (rabbits).
Inhalation: LC50 (4 h) for rats >4.98 mg/l air.
Noel: In 2 y feeding trials, no itl-effects were observed in rats receiving 410 mg/kg diet daily (average) and, in 1 y feeding trials, no ill-effects were observed in dogs receiving 500 mg/kg daily (highest dose treated).
ADI: (JMPR) 0.3 mg/kg b.w. [1986, 1997] (for sum of gtyphosate and its metabolite AMPA).
Water GV Unnecessary to recommend a guideline value because not hazardous to health at concentrations normally found in drinking water`.
Other Not mutagenic, not carcinogenic, not teratogenic, not neurotoxic. No adverse effects on reproduction.
ECOTOXICOLOGY
Birds: Acute oral LD50 for bobwhite quail >3851 mg/kg. Dietary LC50 (8 d) for quail and ducks >4640 mg/kg diet.
Fish: LC50 (96 h) for trout 86, bluegill sunfish 120, harlequin fish 168, sheepshead minnow >1000 mg/l.
Daphnia: LC50 (48 h) 780 mg/l.
Algae: EC50 (72 h) for Selenastrum capricornutum 48.5 mg/l, (7 d) 13.8 mg/l; (96 h) for Skeletonema costatum 1.2 mg/l, (7 d) 0.64 mg/l; (7 d) for Navicula petliculosa 42, Anabaena rios-aquae 15 mg/l.
/Other aquatic spp. LC50 (96 h) for mysid shrimp (Mysidopsis bahia) >1000, grass shrimp 281, fiddler crab 934 mg/l. EC50 (96 h) for sea urchin >1000 mg/l; (14 d) for Lemna gibba 25.5 mg/l. EC50 (48 h) for Litoria moorei tadpole 111 mg/l.
ENVIRONMENTAL FATE
Plant: EHC 159 (WHO, 1994). Animals In mammals, following oral administration, glyphosate is very rapidly excreted unchanged and does not bioaccumulate.
Slowly metabolised to aminomethylphosphonic acid ([1066-51-9]), which is the major plant metabotite.
Soil/Environment: In soil (field), DT50 3-174 d, depending on edaphic and climatic conditions. In water, DT50 varies from a few to 91 d. Photodegradation in water occurs under natural conditions, DT50 ≤2.8 d; no substantial photodegradation in soil was recorded over 31 d. In lab. whole system with water and sediment, DT50 <14 d (aerobic), 14-22 d (anaerobic). The major metabolite in soil and water is aminomethylphosphonic acid.
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