IDENTIFICATION

Common name: Triazophos

Other name: triazophos (BSI, E ISO, (m) F-ISO)

Iupac name: O,O-diethyl O-1-phenyl-lH-1,2,4-triazol-3-yl phosphorothioate

Chemical abstracts name:     O, 0-diethyl O-(1-phenyl-1H-1,2,4-triazol-3-yl) phosphorothioate

Type: Insecticide for Agriculture

CAS RN: [24017 47-8]

M.F.: C₁₂H₁₆N₃O₃PS

Mol Wt: 313.3

 

Form (appearance): Light yellow to dark brown liquid, with a typical phosphate ester odour .

Composition: Tech. grade is ≥92% pure.
M.P.: 0-5℃

B.P.: Exothermic decomposition above 140℃

V.P.: 0.39 mPa (30℃); 13 mPa (55℃)

F.P.: Cannot be determined; exothermic decomposition above 140℃

S.G.: 1.24 (20℃)

Solubility.: In water 39 mg/l (pH 7, 20℃). In acetone, dichloromethane, methanol, isopropanol, ethyl acetate and polyethyleneglycols >500, n-hexane 11.1 (all in g/l, 20℃).

Stability: Stable to light. Hydrolysed by aqueous acids and alkalis.

K_owlogP: 3.34

 

Formulation types: EC; UL.

Biochemistry: Cholinesterase inhibitor.

Mode of action: Broad-spectrum insecticide and acaricide with contact and stomach action. Non systemic, but penetrates deeply into plant tissues.

Uses: Control of aphids, thrips, midges, beetles, lepidopterous larvae, cutworms and other soil insects, spider mites and other species of mite, etc. in ornamentals, fruit trees (including citrus - 0.03%-0.1%), vines, bananas, strawberries, vegetables (200- 600 g/ha), oilseed rape, cereals, sugar beet, sugar cane, maize, soya beans, peanuts, guavas, mangoes, oil palms, olives, cotton (250-600 g/ha), coffee, rice (200-400 g/ha), grassland, and in forestry. Also controls some free living nematodes, particularly in ornamentals and strawberries, and as a bulb dip for tulips and garlic.

 

Oral: Acute oral LD₅₀ for rats 57 59, dogs >320->500 mg/kg b.w. daily.

Skin and eye: Acute dermal LD₅₀ for rats >2000 mg/kg. No skin or eye irritation.

Inhalation: LC₅₀ (4 h) for rats 0.531 mg/l air.

Noel: In 2 y feeding trials, rats receiving 1 mg/kg diet and dogs receiving 0.3 mg/kg diet were unaffected, except for inhibition of blood serum cholinesterase.

ADI: (JMPR) 0.001 rog/kg b.w. [1993].

Toxicity: WHO (a.i.) lb EC hazard T; R23/251Xn; R211 N; RS0, R53

 

Birds: Acute oral LDs0 for Japanese quail 4.2-27.1 rog/kg, depending on carrier and sex. LC₅₀ (8 d) for mallard ducks 325 mg/kg diet.

Fish: LC₅₀ (96 h) for carp 5.6, golden orfe 7.5 18 mg/I. LC₅₀ (21 d) for trout 0.01 mg/l.

Daphnia: LC₅₀ (48 h) 0.003 mg/l.

Algae: LC₅₀ (96 h) 1.15 mg/l.

Worms: LC₅₀ (14 d) for Eisenio foetida 187 mg/kg dry artificial soil. Bees Toxic to honeybees.

 

Plant: EHC 63(WHO, 1986; a general review of organophosphorus insecticides).
In cotton plants, 1-phenyl-3-hydroxy-1,2,4-triazole is found as a metabolite, and the occurrence of a desethyl derivative of triazophos is presumed (W. G. Thier et al., Fresenius`Z. Anal. Chem., 1973, 267, 181 186).

Animals: Mainly eliminated via urine (75 94% of applied radioactivity). Excretion DT₅₀ <1 d.

Soil/Environment: DT₅₀ (aerobic, field) 6-12 d, DT₅₀ 39 114 d. DT₅₀ (lab.) 7 46 d, DT₅₀ 109 181 d. Water: rapidly degraded in aquatic systems;DT₅₀ (elimination from water) <3 d, (elimination from water/sediment system) <11 d; DT₅₀ (elimination from the system) <47 d.