9019. 2,4,5-T

Nomenclature

CAS number: 93-76-5
(2,4,5-Trichlorophenoxy)acetic acid; Esteron 245 (Dow); Trioxone (Zeneca).
C8H5Cl3O3; mol wt 255.48.
C 37.61%, H 1.97%, Cl 41.63%, O 18.79%.

Description and references

Post-emergence herbicide. Prepd from 2,4,5-trichlorophenol: Pokorny, J. Am. Chem. Soc. 63, 1768 (1941); from benzenehexachloride: Galat, ibid. 74, 3890 (1952). Activity: C. L. Hamner, T. B. Tukey, Science 100, 154 (1944). Contains trace levels of TCDD, q.v., as a contaminant: J. Smith, Science 203, 1090 (1979); Chem. Eng. News 59, 6 (Jan. 5, 1981). Toxicity: V. A. Rowe, T. A. Hymas, Am. J. Vet. Res. 15, 622 (1954). See also 2,4-D.

Chemical structure

Properties

Crystals from benzene, mp 153°. d2020 1.80. Soly in water at 30°: 238 mg/kg. Sol in alcohol. Forms water-soluble sodium and alkanolamine salts. Commercial products are usually in the form of amines or esters, often in mixture with 2,4-D. LD50 orally in mice, rats: 389, 500 mg/kg (Rowe, Hymas).

Caution

Potential symptoms of overexposure in exptl animals are ataxia; skin irritation, acne-like rash; liver damage. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 292.

Note

In March 1985 the E.P.A. terminated all registrations for the use of this herbicide on rice fields, orchards, sugarcane, rangeland and other noncrop sites. This follows the 1970 action of the Department of Agriculture halting the use of the pesticide on all food crops except rice: Chem. Eng. News 63, 6 (Mar. 25, 1985).

Use

Formerly as herbicide.