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oxydemeton-methyl (Metasystox-R) Chemical Profile 4/85

                                 oxydemeton-methyl

      CHEMICAL NAME:      S-[2-(ethylsulfinyl)ethyl] O,O-dimethyl
                          phosphorothioate (56)

      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).


                                   I.  EFFICACY

      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

      TOXICOLOGY

           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
      killed (8a).
           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
      Control Center.

      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
      per minute.
      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
      doubled (25).

                        VI.  FIRE AND EXPLOSION INFORMATION

           To be developed.


                                VII.  COMPATIBILITY

           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
                                  (800) 424-9300
                      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.
               30 pp.

       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.

      4/4/85