phosphamidon (Dimecron) Chemical Profile 8/90
CHEMICAL NAME: O,O-dimethyl-O-(2-chloro-2-diethyl carbamoyl-
1-methyl-vinyl) phosphate (56)
TRADE NAME(S): Dimecron (56)
FORMULATION(S): Liquid (8 pounds active gallon), soluble
concentrates (20, 50, and 100% w/v) (56).
TYPE: Organophosphate insecticide
BASIC PRODUCER(S) Ciba-Geigy
P.O. Box 18300
Greensboro, North Carolina 27419
Chevron Chemical Co./Ortho Div.
940 Hensley Street
Richmond, CA 94804
STATUS: Restricted use. Voluntary cancellation by
manufacturer (Ciba-Geigy) in May 1990.
PRINCIPAL USES: Main use against sucking insects, stemborers in rice,
and against aphids in various crops (56).
Important Pests Controlled: Aphids, stemborers, lygusbugs, leafhoppers,
leaf miners, spruce budworm, beetles, thrips, codling moth, grasshoppers,
mites, scale, bollworms, Mexican bean beetles, white flies and many
A systemic translocated compound through both the roots and the
leaves. A selective compound with only slight contact and practically
no ovicidal activity. When mixed with Phaltan (fungicide) a synergistic
effect occurs (8a).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C10 H19 Cl NO5 P (62)
MOLECULAR WEIGHT: 299.7 (62)
PHYSICAL STATE: Yellow liquid (pure compound) (62)
BOILING POINT: 94 C/0.04 mmHg (pure compound) (62)
VAPOR PRESSURE: 3.3 mPa at 20 C (pure compound) (62)
SOLUBILITY: Completely miscible in water at 20 C (pure compound)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: None established
NIOSH RECOMMENDED LIMIT: None established
ACGIH RECOMMENDED LIMIT: None established
A. ACUTE TOXICITY
DERMAL: LD50 = 374 mg/kg (rat); slight irritant to skin of
LD50 = 267 mg/kg (rabbit) (56)
ORAL: LD50 = 17.4 mg/kg (rat) (62)
B. SUBACUTE AND CHRONIC TOXICITY:
In 2-yr feeding trials the NEL was: for rats 1.25 mg/kg daily; for
dogs 0.1 mg/kg daily (62).
Animals placed in an atmosphere containing 0.125 mg/l of
phosphamidon for 6 hours a day, 5 days a week for a period of 90 days
did not show any marked toxic effects (17a).
IV. ENVIRONMENTAL CONSIDERATIONS
Moderately hazardous to birds, fish and beneficial insects.
Hazardous to honey bees. Biological magnification unlikely. Injury has
been reported on certain varieties of fruits and ornamentals (1).
It is highly toxic to birds and honeybees (62).
Fish toxicity: maximum level (ppm) no effect = 100.0
minimum level (ppm) complete kill = 1000.0 (17a).
In tests conducted in Canada, the short term mortality of young
salmon and trout in streams sprayed with phosphamidon was no greater
than that in the unsprayed control site. Phosphamidon applied at
one pound of actual per acre did not affect oysters or the
microorganisms used for food by oysters (17a).
Phosphamidon applied to wooded areas at one pound of actual per
acre did not affect deer, rabbits, mice, chipmunks or toads. However,
some effects on birds have been observed (17a).
Predaceous insect and mite populations have not been seriously
reduced by applications of phosphamidon insecticide (17a).
Approximate Residual Period: 2 weeks as systemic in plants; short life
in soil (1). The initial half-life in and on plants is 1 to 5 days as
a rule (56).
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: 15 ml
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, than at 10-12 hour
intervals if needed. In very severe piosonings, dosage rates may be
VI. FIRE AND EXPLOSION INFORMATION
To be developed.
Corrosive to and decomposed by iron and alkaline materials (1).
Do not mix with copper oxychloride. Do not combine with captan, folpet,
or sulfur. Non-corrosive. Compatible with other pesticides (8a).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Not for use or storage in or around the home
(17b). Poisonous if swallowed, inhaled, or absorbed through skin. Do
not contaminate feed or foodstuffs. Do not get in eyes, on skin or
clothing. Do not breathe mist. Keep container closed. Wash thoroughly
after handling. Do not drink any alcoholic beverage before or during
spraying since alcohol promotes absorption of organic phosphates (56).
PROTECTIVE CLOTHING: Wear natural rubber gloves, protective clothing,
and goggles (17b).
PROTECTIVE EQUIPMENT: Wear a mask or respirator of a type passed by
the U. S. Bureau of Mines for phosphamidon protection (17b).
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.
17a. Chevron Chemical Company, Ortho Division. 1970. Experimental
data sheet: Ortho phosphamidon. San Francisco, CA.
17b. Chevron Chemical Company, Ortho Division. 1974. Specimen label:
Ortho phosphamidon 8 spray. San Francisco, CA.
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
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.