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Acephate - Chemical Profile 4/85


      CHEMICAL NAME:     O,S-Dimethyl acetylphosphoramidothioate (56)


      TRADE NAME(S):     Orthene, Ortran (56)

      FORMULATION(S):    75% soluble powder (56)

      TYPE:              Organophosphate insecticide

      BASIC PRODUCER(S):  Chevron Chemical Co./Ortho Div.
                          940 Hensley Street
                          Richmond, CA 94804

      STATUS:            General use

      PRINCIPAL USES:  Foliage systemic and contact insecticide for insects on
      flowers, vegetables, trees, and shrubs (1).
           Tolerances and labels now exist for use on celery, head lettuce,
      bell peppers, dry and succulent beans, cotton, soybeans, and mint.
      Labelled for cockroach control (spot treatment only) in residential and
      industrial buildings (except food handling establishments), and insect
      control in forests, tobacco, and on ornamentals (56).

                                I.  EFFICACY

           Field trials from 1969-1972 show Orthene to be very effective
      against aphids, bagworms, cankerworms, tent caterpillars, gypsy moth,
      lace bugs, leaf miners, leaf rollers, leafhoppers, mealybugs, oak moth,
      sawflies, pine tip moths, thrips, webworms and other insects attacking
      ornamentals, trees and turf.  Excellent activity has also been
      demonstrated against nuisance pests such as roaches, spiders, crickets,
      ticks and clover mites (17g).

                           II.  PHYSICAL PROPERTIES

      MOLECULAR FORMULA:  C4 H10 NO3 P S (62)

      MOLECULAR WEIGHT:   183.2 (62)

      PHYSICAL STATE:     Colorless solid (technical grade, purity 80-90%)

      MELTING POINT:      82-89 C (technical grade) (62)

      VAPOR PRESSURE:     226 uPa at 24 C (technical grade) (62)

      SOLUBILITY:         At room temperature c. 650 g/l water (technical
                          grade) (62)

                        III.  HEALTH HAZARD INFORMATION

      OSHA STANDARD:  None established

      NIOSH RECOMMENDED LIMIT:  None established

      ACGIH RECOMMENDED LIMIT:  None established


           A.  ACUTE TOXICITY

               DERMAL:  LD50 = >2000 mg/kg (rabbit, technical);
                          >10250 mg/kg (rabbit, Orthene 75% SP) (17g).
                        No irritation or sensitization observed in Guinea
                          pigs (17g).

               ORAL:    LD50 = 945 mg/kg (male rat, technical); 866 mg/kg
                          (female rat, technical); 361 mg/kg (mouse,
                          technical); 1494 mg/kg (rat, Orthene 75% SP) (17g).

               INHALATION:  The vapor pressure of Orthene is low.  Tests in
                            the rat also showed that the vapor toxicity was
                            low.  Four hour exposure to vapors showed no
                            morbidity or mortality in rats and cholinesterase
                            values were normal (technical) (17g).

               EYES:    Slight conjunctival irritation but no corneal opacity
                          or iritis was observed.  Eyes appeared normal after 1
                          week (rabbit, technical) (17g).
                        Moderate irritation and slight iritis after 24 hours;
                          eyes normal after 7 days; no corneal opacity
                          observed.  Dilute sprays were not irritating (rabbit,
                          Orthene 75% SP) (17g).


           In 2-yr feeding trials: dogs showed depression of cholinesterase
      at 100 mg/kg diet (maximum dose level) but no other significant effect;
      rats showed depression of cholinesterase but no effect on weight gain or
      pathological effect at 30 mg/kg diet.  No teratogenic, mutagenic or
      carcinogenic effect was observed (62).
           90-day Subacute Oral Toxicity in Rats:  Feeding Orthene Technical
      for 90 days at dietary levels up to 300 ppm revealed no abnormalities
      in weight gain, food consumption, survival, blood and urologic studies,
      gross and microscopic pathology or organ weights and ratios (17g).
           90-Day Feeding Study in Beagle Dogs:  Levels up to 100 ppm caused
      no significant effects other than depression of cholinesterase (Orthene
      Technical) (17g).
           One-year Feeding Study in Beagle Dogs:  Dietary levels up to 100
      ppm for one year showed no significant differences in the various
      parameters studied except for depression of RBC cholinesterase activity
      at the 100 ppm level.  No gross and histopathologic changes related
      to ingestion of the chemical were noted (Orthene Technical) (17g).


           Some hazard to birds, fish, and beneficial insects.  Hazardous to
      honeybees.  Biological magnification unlikely.  Do not apply to
      American elm, flowering crab apple, sugar maple, or huckleberry (1).
           Toxicity to Fish:  The 96-hr. TL50 is greater than 1000 ppm for
      rainbow trout, 2050 ppm for bluegill, 1725 ppm for large-mouth black
      bass, 2230 ppm for channel catfish, 6650 ppm for mosquito fish
      (Gambusia) and 9550 ppm for goldfish (17g).
           Toxicity to Birds:  Acute Oral LD50 of Orthene Technical:
      350 mg/kg for mallard ducks, 140 mg/kg for ringneck pheasants and
      852 mg/kg for chickens (17g).

      Approximate Residual Period:  10-15 days as systemic; does not
      translocate to new growth.  Short life in soil (1).


           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.


           Symptoms of acute poisoning develop during exposure or within 12
      hours (usually within four hours) of contact.  headACE, DIZZINESS,
      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).


      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
      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).


           To be developed.

                             VII.  COMPATIBILITY

           Compatible with most insecticides and fungicides but must not be
      mixed with alkaline materials such as lime sulfur or Bordeaux (1).

                         VIII.  PROTECTIVE MEASURES

           To be developed.


                                (800) 424-9300

                               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.

      17g. Chevron Chemical Company, Ortho Division.  1973.  Experimental
               data sheet:  Orthene insecticide.  Moorestown, NJ.

      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.