Common name: Oxyfluorfen

Other name: oxyfluorfen (BSI, E-ISO, ANSI, WSSA); oxyfluorfene ((m) F-ISO)

Iupac name: 2-chloro-α,α,α-trifiuoro-p-tolyl-3-ethoxy-4-nitrophenyl ether Chemical Abstracts name 2-chloro-1-(3-ethoxy-4- nitrophenoxy)-4-(trifluoromethyl)benzene

Chemical abstracts name:     [42874-03-3]

Type: Herbicide

M.F.: C₁₅H₁₁ClF₃NO₄

Mol Wt: 361.7

 

Form (appearance): Orange, crystalline solid.

M.P.: 85-90℃; (tech., 65-84℃)

B.P.: 358.2℃ (decomp.)

V.P.: (pure a.i.) 0.0267 mPa (7-5℃)

S.G.: 1.35 (73℃)

Solubility.: In water 0.116 mg/l (25℃). Readily soluble in most organic solvents, e.8. acetone 72.5, cyclohexanone, isophorone 61.5, dimethylformamide >50, chloroform 50-55, mesityl oxide 40-50 (all in g/100 g, 25℃).

Stability: No significant hydrolysis in 28 d at pH 5-9 (25℃). Decomposed rapidly by u.v. irradiation; UT₅₀ 3 d (room temperature). Stable up to 50℃.

K_owlogP: 4.47

 

Formulation types: EC; GR.

Biochemistry: Protoporphyrinogen oxidase inhibitor.

Mode of action: Selective contact herbicide, absorbed more readily by the foliage (and especially the shoots) than by the roots, with very little translocation.

Uses: Control of annual broad-leaved weeds and grasses in a variety of tropical and subtropical crops, by pre- or post-emergence application at rates in the range 0.25-2.0 kg a.i./ha. Particular crops include tree fruit (including citrus), vines, nuts, cereals, maize, soya beans, peanuts, rice, cotton, bananas, peppermint, onions, garlic, ornamental trees and shrubs, and conifer seedbeds.

Phytotoxicity: Soya beans and cotton may be injured by contact with oxyfiuorfen.

 

Oral: Acute oral LD₅₀ for rats and dogs >5000 mg/kg.

Skin and eye: Acute percutaneous LD₅₀ for rabbits >10000 mg/kg. Mild to moderate eye irritant; mild skin irritant (rabbits).

Inhalation: LC₅₀ >5.4 mg/l.

Noel: In chronic dietary trials, NOEL for rats 40, dogs 100, mice 2 mg/kg diet.

ADI: 0.003 mg/kg.

Toxicity: WHO (a.i.) III (Table 5); EPA (formulation) IV

 

Birds: Acute LD₅₀ for bobwhite quail >2150 mg/kg. Dietary LC₅₀ (8 d) for mallard ducks and bobwhite quail >5000 ppm.

Fish: LC₅₀ (96 h) for bluegill sunfish 0.2. trout 0.41, channel catfish 0.4 mg/l.

Daphnia: LC₅₀ (48 h) 1.5 mg a.i./l.

Worms: Bees Not toxic to honeybees at 0.025 mg a.i./bee.

 

Plant: Not readily metabolised in plants.

Animals: For details of metabolism, see I. L. Adler et al., J. Agric. Food Chem., 1977, 25, 1339.

Soil/Environment: Strongly adsorbed on soil, not readily desorbed, and shows negligible leaching. K_oc from 2891 (sand) to 32381 (silty clay loam). Photodecomposition in water is rapid, and on soil is slow. Microbial degradation is not a major factor. Field dissipation DT₅₀ 5-55 d; soil DT₅₀ (in dark) (aerobic) 292 d, (anaerobic) c. 580 d.