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dicrotophos (Bidrin) Chemical Profile 4/85


      CHEMICAL NAME:      3-(dimethoxy-phosphinyloxy)-N,N-dimethylcis-
                          crotonamide (15b)


      TRADE NAME(S):      Bidrin (56)

      FORMULATION(S):  240 grams/liter water soluble concentrate and ULV spray.
      Shell Chemical Co. formulates an 82% w/w water-miscible product, Bidrin 8
      water miscible insecticide (56).

      TYPE:               Organophosphate insecticide

      BASIC PRODUCER(S):  Shell Chemical Co.
                          Div. of Shell Oil
                          P.O. Box 3871
                          Houston, TX 77001

      STATUS:             Restricted use

      PRINCIPAL USES:  Contact and systemic on ornamentals and fruit crops (1).
      Used to control certain economically important pests of cotton.  Also for
      coffee borer control.  Dicrotophos available for control of elm bark
      beetles (tree injection system).  Enters plant tissue rapidly, thus
      enabling many beneficial insects to survive (56).

                                  I.  EFFICACY

      Important Pests Controlled:  Aphids, mites, thrips, fleahoppers,
      grasshoppers, boll weevils, lygus bugs, rice stemborers, bollworms,
      leafminers, stinkbugs, leafhoppers and many others (8a).
           Fast acting.  More than 50% of the material is absorbed into the
      plant within 8 hours of application.  7-21 days control can be expected

                              II.  PHYSICAL PROPERTIES

      MOLECULAR FORMULA:  C8 H16 NO5 P (62)

      MOLECULAR WEIGHT:   237.2 (62)

      PHYSICAL STATE:     Yellowish liquid (pure compound); amber liquid
                          (technical grade, contains about 85% (E)-isomer)

      BOILING POINT:      130 C/0.1 mmHg (pure compound); 400 C/760 mmHg
                          (technical grade) (62).

      VAPOR PRESSURE:     9.3 mPa at 20 C (pure compound); 13 mPa at 20 C
                          (technical grade) (62).

      SOLUBILITY:         Totally miscible with water (technical grade) (62)

                           III.  HEALTH HAZARD INFORMATION

      OSHA STANDARD:  None established

      NIOSH RECOMMENDED LIMIT:  None established

      ACGIH RECOMMENDED LIMIT:  TWA (Time Weighted Average) = 0.25 mg/m3; skin
                                notation (15c).


           A.  ACUTE TOXICITY

               DERMAL:  LD50 for rats ranges from 111-136 mg/kg to 148-181
                          mg/kg, depending on the carrier and the conditions of
                          the test; for rabbits 224 mg/kg, slight irritant to
                          their skin (62).

               ORAL:    LD50 = 22 mg/kg (rat) (15b)
                        LD50 = 17-22 mg/kg (rat) (62)

               INHALATION:  One hour exposure to 910 mg/m3 technical and 2.62
                            mg/L of 38% dicrotophos was fatal in 80 and 20% of
                            male rats respectively.  Exposure to concentrations
                            of 0.61 mg/L technical or 2.12 mg/L of 38%
                            dicrotophos resulted in illness with rapid recovery
                            on removal from exposure (15b).

                            LC50 (4-hr) c.90 mg/m3 air (62).

               EYES:    Slight irritant to eyes of rabbits (62).


           Rats were fed dicrotophos at concentrations of 0, 1, 10 and 100
      ppm in their diets for two years.  There were no detectable effects at
      the 1 ppm concentration.  At the higher concentrations there were
      effects such as decreased body weights (in comparison to controls) or
      reduced cholinesterase concentrations (15b).
           Dogs given dicrotophos in their diets at 0, 0.16, 1.6, and 16 ppm
      for 2 years showed some instances of slight excessive salivation and at
      the 100 ppm concentration fairly consistent excessive salivation, soft
      stools and/or tremors.  There were no other differences between treated
      animals and controls up to the 16 ppm concentration.  At 16 ppm
      cholinesterase concentration, both plasma and erythrocyte, was decreased
           NEL in a 3-generation reproduction study with rats was 2 mg/kg
      daily.  It is not neurotoxic to hens (62).


           Some hazard to birds, fish, and beneficial insects.  Hazardous to
      honey bees.  Biological magnification unknown.  Nonphytotoxic except
      for some varieties of grain seed (1).
           Dicrotophos is a hydrophilic compound and was shown to be leachable
      through soil (Corey 1965).  C14-dicrotophos was shown to breakdown
      rapidly in a moist (50% field capacity) sandy loam soil, only 18.5% being
      recovered after seven to eight days.  The rate of breakdown increased
      with the moisture content.  The hydrolysis of dicrotophos is slow in
      water, suggesting that biological degradation might be important in soil.
      In field soils (Elgar and MacDonald 1966), dicrotophos (applied as
      granules, not incorporated) had an initial half-life of a few days and
      monocrotophos residues were not detected at the 0.1-ppm level after eight
      weeks from application of dicrotophos at up to eight lb./A (35).
           Dicrotophos is relatively stable in neutral or acid solution.  It is
      more prone to hydrolysis in alkali than in acid, although less so than
      many organophosphate insecticides.  It was recovered (>95%) unchanged
      after two hours in sodium carbonate solution (0.25%, pH 11.5) under
      conditions where nine other insecticides showed greater loss (Sun and
      Johnson 1965) (35).
           LC50 (24-hr) is: for mosquito fish 200 mg/l; for harlequin fish
      >1000 mg/l.  It is very toxic to honey bees but because surface residues
      rapidly decline little effect is seen in practice.  Acute oral LD50 for
      birds 1.2-12.5 mg/kg (62).

      Approximate Residual Period:  As systemic lasts 7 to 21 days (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.  HEADACHE, 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:  If the patient's skin is in contact with Bidrin,
      take steps to prevent continuing exposure.  If the insecticide has been
      spilled or splashed onto the clothes or the skin, remove the
      contaminated clothing immediately and wash the skin thoroughly with
      soap and water; use lots of water in rinsing.  Get medical attention

           INGESTION:  Induce vomiting immediately by giving 2 tablespoons
      of Syrup of Ipecac and 2 glasses of water to an adult.  For a child
      give 1 tablespoon plus 1 glass water.  If Syrup of Ipecac not
      available, give 2 glasses of water and tickle the back of the throat
      with a finger.  If not successful at inducing vomiting, do not waste
      time with further attempts.  Get medical attention (18b).

           INHALATION:  Remove patient to fresh air.  Get medical attention

           EYE CONTACT:  Wash out eyes immediately.  Flush the eyes
      continuously with running water for 15 minutes and get medical attention


      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

           Bidrin will burn if exposed to an ignition source.  When exposed to
      excessive heat from a fire, containers may rupture violently, releasing
      toxic and noxious vapors which would be injurious by inhalation or by
      skin contact.  Adjacent Bidrin should be kept cool, if possible, by use
      of water spray (18b).

                                 VII.  COMPATIBILITY

           Generally compatible, but not ordinarily used with other materials

                             VIII.  PROTECTIVE MEASURES

      STORAGE AND HANDLING:   Do not swallow or get into eyes, on skin, or on
      clothing.  Do not breathe vapors.  Not for use or storage in or around
      home.  Do not contaminate food or feed products.  Keep away from heat
      and open flame (56).

      PROTECTIVE CLOTHING:  Clean, liquid-resistant protective clothing --
      including rubber gloves, boots, body covering, and hat -- as required.
      Rubber gloves should be replaced frequently and the discarded gloves
      destroyed to prevent reuse (18b).

      PROTECTIVE EQUIPMENT:  Goggles.  If engineering controls are inadequate
      or cannot be applied, respirators should be used to prevent inhalation
      of vapors or mist.  Follow OSHA rules and regulations regarding
      respiratory protection (18b).

                       IX.  PROCEDURES FOR SPILLS AND LEAKS

                                  (800) 424-9300

           Immediately isolate the affected area and keep out unauthorized
      personnel.  Cleanup should be handled by trained and properly equipped
      pesticide decontamination personnel (18b).

                               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.

      15b. American Conference of Governmental Industrial Hygienists.  1971.
               Documentation of the threshold limit values for substances in
               workroom air with supplements for those substances added or
               changed since 1971, 3rd ed., 4th printing (1977).  Cincinnati,
               OH.  484 pp.

      15c. American Conference of Governmental Industrial Hygienists.  1984.
               TLVs:  threshold limit values for chemical substances and
               physical agents in the work environment and biological exposure
               indices with intended changes for 1984-85.  Cincinnati, OH.
               116 pp.

      18b. Shell Chemical Company.  1981.  Agricultural chemicals safety
               manual:  Bidrin insecticide safety guide.  Houston, TX.

      25.  Morgan, D.P.  1982.  Recognition and management of pesticide
               poisonings, 3rd ed.  U.S. Environmental Protection Agency,
               Washington, DC.  120 pp.

      35.  Beynon, K.I., D.H. Hutson, and A.N. Wright.  1973.  The
               metabolism and degradation of vinyl phosphate
               insecticides.  Residue Rev.  47:55-142.

      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.