PMEP Home Page --> Pesticide Active Ingredient Information --> Insecticides and Miticides --> Insecticides, D to E --> Dimethoate --> Dimethoate - Chemical Profile 4/85

Dimethoate - Chemical Profile 4/85

                                     dimethoate

      CHEMICAL NAME:      O,O-Dimethyl S-(N-methylcarbamoylmethyl)
                          phosphorodithioate (56)

      DEC INGRED. CODE:

      TRADE NAME(S):      Cygon, Rebelate (56)

      FORMULATION(S):     Emulsifiable concentrate, wettable powder, dust (56)

      TYPE:               Organophosphate insecticide - miticide

      BASIC PRODUCER(S):  American Cyanamid Co.         BASF Wyandotte Corp.
                          Agr. Res. Div.                Agr. Chem. Div.
                          P.O. Box 400                  P.O. Box 181
                          Princeton, NJ 08540           Parsippany, NJ 07054

      STATUS:             General use

      PRINCIPAL USES:  Used as a residual wall spray in farm buildings for
      controlling house flies, and to control a wide range of insects and
      mites on ornamental plants, many vegetables, cotton, sorghum, alfalfa,
      watermelons, apples, pears, pecans, safflower, wheat, lemons, oranges,
      grapefruit, tangerines, melons, tobacco, grapes, tomatoes, corn,
      soybeans (56).  As systemic on plants for sucking insects and mites (1).

                                I.  EFFICACY

      Important Pests Controlled:  Aphids, mites, codling moths, grasshoppers,
      plum curculio, pear psylla, scale, leafhoppers, thrips, loopers,
      Drosophila, lygus bugs, leafminers, flies, olive flies, whiteflies,
      Hassids, houseflies and many others (8a).
           Effective against many insect larvae.  Moves throughout the plant
      rapidly.  Relatively slow acting against houseflies but with up to 8
      weeks residual control.  Used to control fly maggots in manure piles
      (8a).
           It is effective against houseflies and Diptera of medical importance
      (62).

                           II.  PHYSICAL PROPERTIES

      MOLECULAR FORMULA:  C5 H12 N O3 P S2 (62)

      MOLECULAR WEIGHT:   229.2 (62)

      PHYSICAL STATE:     Colorless crystals (pure compound); white to grayish
                          crystals (technical grade, 96% pure) (62).

      MELTING POINT:      51-52 C (pure compound); 45-47 C (technical grade)
                          (62).

      VAPOR PRESSURE:     1.1 mPa at 25 C (pure compound) (62)

      SOLUBILITY:         25 g/l water at 21 C (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 = >1000 mg/kg (guinea pig, 50% a.i. solution) (56)
                        LD50 = >800 mg/kg (rat); no irritation developed after
                          the application of 130 mg a.i. (as e.c.)/20 cm2 to
                          shaved skin of rabbits (62).

               ORAL:    LD50 (rat) = 500-600 mg a.i./kg (male), 570-680 mg/kg
                          (female); 180-325 mg tech./kg (male), 240-336 mg/kg
                          (female) (62).
                        LD50= 215 mg/kg (male albino rat) (56).

           B.  SUBACUTE AND CHRONIC TOXICITY:

           In feeding trials (90-day to 1-yr) NEL in rats for cholinesterase
      inhibition was 1.0-32 mg/kg diet.  Human volunteers in trials up to 57
      days showed NEL for cholinesterase inhibition at 15 mg daily (62).

                       IV.  ENVIRONMENTAL CONSIDERATIONS

           Some hazard to birds and fish.  Hazardous to honey bees.
      Biological magnification unlikely.  Injurious to certain varieties of
      walnuts, pines, tomatoes, and beans.  Russeting appears on red and Golden
      Delicious apples (1).
           Acute oral LD50: for male pheasants 15 mg/kg; for female ducks 40
      mg/kg.  LC50 (96-hr) for mosquito fish is 40-60 mg/l.  LD50 for honeybees
      is 0.9 ug/bee (62).

      Approximate Residual Period:  1-3 weeks on plant surfaces; very short
      life in soil and water.  Several weeks residual control of house flies
      in barns (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 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 poisoning, dosage rates may be
      doubled (25).

                      VI.  FIRE AND EXPLOSION INFORMATION

           To be developed.

                              VII.  COMPATIBILITY

           Compatible with insecticides and fungicides that are not alkaline
      in reaction (8a).

                           VIII.  PROTECTIVE MEASURES

      STORAGE AND HANDLING:   Harmful or fatal if swallowed, inhaled, or
      absorbed through skin.  Do not get in eyes, on skin, on clothing.  Do
      not breathe dust, keep container closed.  Use with adequate
      ventilation.  Wash thoroughly after handling.  Do not contaminate food
      or feed products.  Liquid formulations must be stored above 45 F.
      The biological activity remains practically unvaried for 2 years under
      environmental conditions, provided stored in unopened and undamaged
      original containers, in shaded and possibly well-aired places (56).

      PROTECTIVE CLOTHING:  See product label.  Generally, impervious gloves,
      boots, body-covering clothing, wide brimmed hat, and respirator (56).

                     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.

      4/24/85