fenthion (Baytex, Entex) Chemical Profile 4/85
CHEMICAL NAME: O,O-Dimethyl O-[3-methyl-4-(methylthio)phenyl]
DEC INGRED. CODE:
TRADE NAME(S): Baytex (Mobay Chemical Corp.); Baycid, Entex, Baytex,
Lebaycid, Tiguvon (Bayer AG) (56).
FORMULATION(S): Spray concentrate, liquid concentrate (Baytex);
spray concentrate (Entex); pour-on, ready-to-use
solution (Tiguvon); emulsifiable concentrate,
wettable powder, ULV, granular, dust (Lebaycid) (56).
TYPE: Organophosphate insecticide
BASIC PRODUCER(S): Mobay Chemical Company
Agricultural Chemicals Division
P.O. Box 4913
Kansas City, MO 64120
Pflanzenschutz Zentrum Monheim
Bayerwerk, West Germany
STATUS: Restricted use
PRINCIPAL USES: Baytex for effective control of mosquitoes and flies
as well as insect pests on ornamental plants.
Entex Spray Concentrate is registered in the U.S. and Canada for
additional use by pest control operators.
Tiguvon is registered for control of cattle grubs, flies, and
lice; and as Spotton for controlling cattle grubs on beef cattle.
Lebaycid for controlling leafhoppers, cereal bugs, and rice stem
borers. It is outstanding for its effectiveness against fruit flies
Baytex combines long residual effect with a wide range of
insecticidal effectiveness. One of its outstanding characteristics is
the excellent control of flies, mosquitoes, ticks, roaches, and lice
that have become resistant to chlorinated hydrocarbons. Another
feature of this compound is its residual activity on alkaline surfaces.
Sprays can be applied to fresh whitewash without deleterious effects to
the insecticide and without staining the whitewash (38a).
Important Pests Controlled: Flies, mosquitoes, roaches, ticks, lice,
bedbugs, crickets, armyworms, cattle grubs, thrips, leafminers, codling
moth, psylla, bollworm, horn flies, fleas, aphids, leafhoppers, ants,
mites and others (8a).
It has given control of insects in stored products from four to
sixteen months. It gave 100% control of mosquitoes after forty-two weeks
when applied to the sides of barns (8a).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C10 H15 O3 P S2 (62)
MOLECULAR WEIGHT: 278.3 (62)
PHYSICAL STATE: Colorless liquid (pure compound); brown oil
(technical product, 95-98% pure) (62).
ODOR: Weak garlic odor (technical product) (62)
BOILING POINT: 87 C/0.01 mmHg (pure compound) (62)
VAPOR PRESSURE: 4 mPa at 20 C (pure compound) (62)
SOLUBILITY: 2 mg/kg water at 20 C (pure compound) (62)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: None established
NIOSH RECOMMENDED LIMIT: None established
ACGIH RECOMMENDED LIMIT: TWA (Time Weighted Average) = 0.2 mg/m3;
skin notation (15c).
A. ACUTE TOXICITY
DERMAL: LD50 = 330-500 mg/kg (rat); more toxic to dogs and
LD50 = 1680 mg/kg (technical product, male rat);
2830 mg/kg (technical product, female rat) (56).
ORAL: LD50 (rat) = 190-315 mg/kg (male); 245-615 mg/kg
LD50 = 255-298 mg/kg (technical product, rat) (56)
INHALATION: LC50 (mg/l/60 min) = 3000 (male rat); 2400
(female rat) (38a).
B. SUBACUTE AND CHRONIC TOXICITY:
In 2-yr feeding trials NEL for rats 3 mg/kg diet; in 1-yr trials
dogs receiving 50 mg/kg diet showed no loss of weight or food consumption
IV. ENVIRONMENTAL CONSIDERATIONS
Some hazard to birds, fish and beneficial insects. Hazardous to
honey bees. Biological magnification unlikely. Phytotoxic to American
linden, Hawthorne rose and sugar maple (1).
Oxidation to the sulphoxide and sulphone, both highly insecticidal,
proceeds in plants (62).
Don't apply for mosquito control in areas containing fish, shrimp,
crabs, or cray fish (8a).
LC50 (96-hr) for carp 2.5-3.3 mg/l; LC50 (48-hr) for goldfish 1.9
Approximate Residual Period: 4-6 weeks (1).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed
from original source documents, primarily from "Recognition and
Management of Pesticide Poisonings", 3rd ed. by Donald P. Morgan,
which have been footnoted. This information has been provided in
this form for your convenience and general guidance only. In
specific cases, further consultation and reference may be required
and is recommended. This information is not intended as a sub-
stitute for a more exhaustive review of the literature nor for the
judgement of a physician or other trained professional.
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
FREQUENT SYMPTOMS AND SIGNS OF POISONING BY ORGANOPHOSPHATE PESTICIDES
Symptoms of acute poisoning develop during exposure or within 12
hours (usually within four hours) of contact. HEADACHE, DIZZINESS,
WEAKNESS, INCOORDINATION, MUSCLE TWITCHING, TREMOR, NAUSEA, ABDOMINAL
CRAMPS, DIARRHEA, and SWEATING are common early symptoms. Blurred or
dark vision, confusion, tightness in the chest, wheezing, productive
cough, and PULMONARY EDEMA may occur. Incontinence, unconsciousness
and convulsions indicate very severe poisoning. SLOW HEARTBEAT,
salivation, and tearing are common. TOXIC PSYCHOSIS, with manic or
bizarre behavior, has led to misdiagnosis of acute alcoholism. Slowing
of the heartbeat may rarely progress to complete sinus arrest.
RESPIRATORY DEPRESSION may be fatal. Continuing daily absorption of
organophosphate at intermediate dosage may cause an INFLUENZA-LIKE
ILLNESS characterized by weakness, anorexia, and malaise (25).
SKIN CONTACT: Bathe and shampoo victim with soap and water if
there is any chance that skin and hair are contaminated (25).
INGESTION: If victim is alert and respiration is not depressed,
give Syrup of Ipecac, followed by 1-2 glasses of water to induce
vomiting. Adults (12 years and over): 30 ml; children under 12 years: 15
INHALATION: If inhaled, remove to fresh air. If not breathing,
give artificial respiration, preferably mouth to mouth. Get medical
EYE CONTACT: If eyes are contaminated, wash with plenty of water
for at least 15 minutes (38a).
NOTES TO PHYSICIAN:
Administer ATROPINE SULFATE intravenously, or intramuscularly, if IV
injection is not possible.
In MODERATELY SEVERE poisoning: Adult dosage: 0.4-2.0 mg repeated
every 15 minutes until atropinization is achieved: tachycardia (pulse
of 140 per minute), flushing, dry mouth, dilated pupils. Maintain
atropinization by repeated doses for 2-12 hours or longer depending on
severity of poisoning.
Dosage for children under 12 years: 0.05 mg/kg body weight, repeated
every 15 minutes until atropinization is achieved. Maintain
atropinization with repeated dosage of 0.02-0.05 mg/kg.
SEVERELY POISONED individuals may exhibit remarkable tolerance to
atropine; two or more times the dosages suggested above may be needed.
Administer PRALIDOXIME (Protopam (TM)-Ayerst, 2-PAM) in cases of severe
poisoning in which respiratory depression, muscle weakness and
twitchings are severe.
Adult dosage: 1.0 gm intravenously at no more than 0.5 gm per minute.
Child's dose (under 12 years): 20-50 mg/kg (depending on severity of
poisoning) intravenously, injecting no more than half the total dose
Dosage of pralidoxime may be repeated in 1-2 hours, then at 10-12 hour
intervals if needed. In very severe poisonings, dosage rates may be
VI. FIRE AND EXPLOSION INFORMATION
To be developed.
Believed compatible with most insecticides and fungicides except
highly alkaline materials (1).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Store in a cool, dry area. Store the liquid
formulations away from excessive heat and open flame. Store in an area
designated specifically for pesticides. Do not store near any material
intended for use or consumption by humans or animals (38a).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
X. LITERATURE CITED
1. Harding, W.C. 1979. Pesticide profiles, part one: insecticides
and miticides. Univ. Maryland, Coop. Ext. Serv. Bull. 267.
8a. Thomson, W. T. 1976. Agricultural chemicals - book 1:
insecticides, acaricides, and ovicides. Revised ed. Thomson
Publ., Indianapolis, IN. 232 pp.
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
38a. Mobay Chemical Corporation, Agricultural Chemicals Division.
1981. Technical information: Baytex insecticide.
Kansas City, MO.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.
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