oxydemeton-methyl (Metasystox-R) Chemical Profile 4/85
CHEMICAL NAME: S-[2-(ethylsulfinyl)ethyl] O,O-dimethyl
DEC INGRED. CODE:
TRADE NAME(S): Metasystox-R (56)
FORMULATION(S): Emulsifiable concentrate (56)
TYPE: Organophosphate insecticide-miticide
BASIC PRODUCER(S): Mobay Chemical Corp., Agricultural Chemicals Div.
P.O. Box 4913
Kansas City, MO 64120
STATUS: General use
PRINCIPAL USES: Effective control by contact and systemic action of
many destructive pests that attack certain vegetable, fruit, and field
crops as well as ornamental flowers, shrubs, and trees. Primarily
effective against aphids, mites, thrips, and sawflies (56).
Important Pests Controlled: Mites, aphids, white flies, sawflies,
thrips, leafhoppers and many others (8a).
Capable of being translocated into the sap stream giving it a
residual effectiveness since it is not washed off. Selective, giving
quick knock-down effects (8a).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C6 H15 O4 P S2 (62)
MOLECULAR WEIGHT: 246.3 (62)
PHYSICAL STATE: Clear amber-colored liquid (pure compound) (62)
MELTING POINT: <-10 C (pure compound) (62)
BOILING POINT: 106 C/0.01 mmHg (pure compound) (62)
SOLUBILITY: Miscible in water (pure compound) (62)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: None established
NIOSH RECOMMENDED LIMIT: None established
ACGIH RECOMMENDED LIMIT: None established
A. ACUTE TOXICITY
DERMAL: LD50 = 250 mg/kg (rat, technical product) (56)
ORAL: LD50 = 65-75 mg/kg (rat, technical product) (56)
B. SUBACUTE AND CHRONIC TOXICITY:
In 84-day feeding trials rats receiving 20 mg/kg diet suffered a
slight cholinesterase depression (62).
IV. ENVIRONMENTAL CONSIDERATIONS
Some hazard to birds, fish and beneficial insects. Moderately
hazardous to honey bees. Biological magnification unlikely. Some
injury to certain ornamentals has been reported especially in
combination with other pesticides (1).
Toxic to fish and wildlife. Birds feeding on treated areas may be
LC50 (24 hr) for rainbow trout and bluegill is 10 mg/l (62).
Approximate Residual Period: 3 weeks as systemic in plants (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 ml (25).
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.
Compatible with most materials except those of alkaline nature
(1). Don't use in combination with Euparen or Morestan (8a).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Do not handle treated ornamentals until the spray
has dried (8a).
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.
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.