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oxadiazon (Ronstar) Herbicide Profile 2/85

                                     oxadiazon
      CHEMICAL NAME:      2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-
                          -1,3,4-oxadiazolin-5-one (56)
      TRADE NAME(S):      Ronstar (56)
      FORMULATION(S):     Emulsifiable concentrates, granules, flowable (56).
                          Ronstar 0.24 kg/l (2 lb/gal EC), Chipco Ronstar
                          G (2% granular) (58).
      TYPE:               Oxadiazolinone herbicide
      BASIC PRODUCER(S):  Rhone-Poulenc, Inc., Agricultural Div.
                          P.O. Box 125
                          Monmouth Junction, NJ 08852
      STATUS:             General use
      PRINCIPAL USES:  Provides preemergence and early postemergence
      control of annual grasses and broadleaf weeds.  Registered in the U.S.
      and France as a selective preemergent herbicide for control of annual
      grasses and broadleaf weeds in turf and ornamentals (56).
      APPLICATION METHOD(S):  Aerial or ground applications preemergence and
      shows some activity early postemergence (58).
                                   I.  EFFICACY
           Shows promise in rice, turf, orchards, peanuts, soybeans, and
      ornamentals for control of grasses and broadleaf weeds such as:
           Grasses                              Broadleaves
           _______                              ___________
      Annual bluegrass                Florida beggarweed   Prickly sida
      Barnyardgrass                   Carpetweed           Prostrate knotweed
      Crabgrass                       Cudweed              Purslane
      Fall panicum                    Dayflower            Redmaids
      Yellow, green, giant foxtail    Ducksalad            Smartweed
      Goosegrass                      Filaree              Sowthistle
      Junglerice                      Groundsel            Velvetleaf
      Signalgrass                     Jimsonweed           Morningglory
      Sprangletop                     Lambsquarters        Black nightshade
      Texas panicum                   Mustards
      Hophornbeam copperleaf          Pigweed (58)
                             II.  PHYSICAL PROPERTIES
      MOLECULAR FORMULA:  C15 H18 Cl2 N2 O3 (62)
      MOLECULAR WEIGHT:   345.2 (62)
      PHYSICAL STATE:     Colorless crystals (pure compound) (62)
      ODOR:               Odorless (pure chemical) (58)
      MELTING POINT:      c. 90 C (pure compound) (62)
      VAPOR PRESSURE:     <133 uPa at 20 C (pure compound) (62)
      SOLUBILITY:         0.7 mg/l water at 20 C (pure compound) (62)
                          III.  HEALTH HAZARD INFORMATION
      OSHA STANDARD:  NA
      NIOSH RECOMMENDED LIMIT:  NA
      ACGIH RECOMMENDED LIMIT:  NA
      TOXICOLOGY
           A.  ACUTE TOXICITY
               DERMAL:  LD50 = >8000 mg/kg, mild irritant (rat, technical);
                          8000 mg/kg, severe skin irritation (rabbit, Ronstar
                          2 lb/gal EC); >10,000 mg/kg, moderate skin
                          irritation (rabbit, Chipco Ronstar G) (58).
                        Oxadiazon has been shown to be nonirritating and
                          nonsensitizing when applied to normal intact skin
                          (58).
               ORAL:    LD50 = >8000 mg/kg (rat, mouse, technical); 2.31 ml/kg
                          (rat, Ronstar 2 lb/gal EC); >30,000 mg/kg (rat,
                          Chipco Ronstar G) (58).
               INHALATION:  LC50 = >200 mg/l (rat, technical); LD50 = >34
                            mg/l (Ronstar 2 lb/gal EC) (58).
               EYES:    Primary eye irritation:  mild transient irritant
                        (technical); severe (Ronstar 2 lb/gal EC); severe
                        when not followed by a washout (Chipco Ronstar G)
                        (58).
           B.  SUBACUTE AND CHRONIC TOXICITY:
           In feeding trials rats and dogs receiving 25 mg/kg daily were not
      affected (62).
           Subacute dermal LD50 (rabbit): >7000 mg/kg (58).
           Two-year feeding studies in rats and dogs showed that the level of
      no adverse effect is at least 100 ppm of the total dietary intake in
      both species (58).
                        IV.  ENVIRONMENTAL  CONSIDERATIONS
           The acute oral LD50 is:  for bobwhite quail 6000 mg/kg; for
      mallard duck 1000 mg/kg (62).
           The LC50 in fresh water fish is >2 ppm for all species tested
      (58).
           It is strongly adsorbed by soil colloids (and humus) and very
      little migration or leaching occurs.
           Presents no danger for soil microorganisms at rates likely to be
      applied in the field.
           There is negligible loss of oxadiazon due to volatilization under
      normal field conditions (58).
                      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.
      KNOWN OR SUSPECTED ADVERSE EFFECTS:  Irritating to skin and eyes (25).
           SKIN CONTACT:  Wash contaminated skin with soap and water (25).
           INGESTION:  Ingestions of small amounts (less than 10 mg/kg
      body weight) occurring less than an hour before treatment, are probably
      best treated by:  Syrup of Ipecac, followed by 1-2 glasses of water.
      Dose for adults and children over 12 years:  30 ml.  Dose for children
      under 12 years:  15 ml (25).
           EYE CONTACT:  Flush contaminated eyes with copious amounts of
      fresh water for 15 minutes (25).
      NOTES TO PHYSICIAN:
      INGESTIONS of LARGE amounts (more than 10 mg/kg) occurring less than an
      hour before treatment, should probably be treated by gastric lavage:
      A.   INTUBATE stomach and ASPIRATE contents.
      B.   LAVAGE stomach with slurry of ACTIVATED CHARCOAL IN 0.9% saline.
           Leave 30-50 gm activated charcoal in the stomach before
           withdrawing tube.
      C.   SODIUM SULFATE, 0.25 gm/kg in tap water, as a cathartic.
           CAUTION:  Hydrocarbons (kerosene, petroleum distillates) are
                     included in some formulations of these chemicals.
                     Ingestion of very LARGE AMOUNTS may cause CNS
                     depression.  In this case, IPECAC IS CONTRAINDICATED.
                     Also, gastric intubation incurs a risk of HYDROCARBON
                     PNEUMONITIS.  For this reason observe the following
                     precautions:
                     (1)  If the victim is unconscious or obtunded and
                          facilities are at hand, insert an ENDOTRACHEAL TUBE
                          (cuffed, if available) prior to gastric intubation.
                     (2)  Keep victim's HEAD BELOW LEVEL OF STOMACH during
                          intubation and lavage (Trendelenburg, or left
                          lateral decubitus, with head of table tipped
                          downward).  Keep victim's head turned to the left.
                     (3)  ASPIRATE PHARYNX as regularly as possible to remove
                          gagged or vomited stomach contents.
      INGESTIONS occurring MORE THAN an HOUR before treatment are probably
      best treated only by ACTIVATED CHARCOAL, 30-50 gm, and SODIUM or
      MAGNESIUM SULFATE, 0.25 gm/kg, as described above.
      There are no specific antidotes for these chemicals.  Because
      manifestations of toxicity do occasionally occur in peculiarly
      predisposed individuals, MAINTAIN CONTACT with victim for at least 72
      hours so that unexpected adverse effects can be treated promptly (25).
                        VI.  FIRE AND EXPLOSION INFORMATION
           Technical material is not flammable.  For formulated
      emulsifiable concentrate, use ordinary precautions for volatile
      solvents (58).
                                VII.  COMPATIBILITY
           Noncorrosive (58).
                             VIII.  PROTECTIVE MEASURES
      STORAGE AND HANDLING:  Stable in excess of 2 years.  Avoid contact with
      skin and clothing (58).
                       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
      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.
      58.  Weed Science Society of America, Herbicide Handbook Committee.
               1983.  Herbicide handbook of the weed science society of
               America, 5th ed.  Weed Science Society of America, Champaign,
               IL.  515 pp.
      62.  The Pesticide Manual:  A World Compendium, 7th ed.  1983.  C.R.
               Worthing, ed.  The British Crop Protection Council, Croydon,
               England.  695 pp.
      2/13/85