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bromacil (Hyvar X, XL) Herbicide Profile 2/85

      CHEMICAL NAME:      5-Bromo-3-sec-butyl-6-methyluracil (56)
      TRADE NAME(S):      Hyvar X, Hyvar XL (56)
      FORMULATION(S):     Wettable powder (80%) (Hyvar X); water-soluble
                          liquid (2 pounds/gallon) (Hyvar X-L).  40.8%, 4
                          pounds bromacil per gallon (Bromax 4L).  Various
                          granular and liquid formulations are available
                          from formulators (56).
      TYPE:               Herbicide
      BASIC PRODUCER(S):  E.I. duPont de Nemours and Co., Inc.
                          Biochemicals Dept.
                          1007 Market St.
                          Wilmington, DE 19898
      STATUS:             General use
      PRINCIPAL USES:  For general weed or brush control in noncrop areas;
      particularly useful against perennial grasses.  Also recommended for
      selective weed control in pineapple and citrus (56).
      APPLICATION METHOD(S):  Bromacil is sprayed or spred dry (as granules,
      etc.) on the soil surface, preferably just before or during a period of
      active growth of weeds (58).
                                   I.  EFFICACY
           To be developed.
                             II.  PHYSICAL PROPERTIES
      MOLECULAR FORMULA:  C9 H13 Br N2 O2 (62)
      MOLECULAR WEIGHT:   261.1 (62)
      PHYSICAL STATE:     Colorless crystalline solid (pure chemical) (62)
      ODOR:               Odorless (pure chemical) (58)
      MELTING POINT:      158-159 C (pure chemical) (62)
      VAPOR PRESSURE:     33 uPa at 25 C (pure chemical) (62)
      SOLUBILITY:         815 mg/l water at 25 C (pure chemical) (62)
                          III.  HEALTH HAZARD INFORMATION
      ACGIH RECOMMENDED LIMIT:  TWA (Time Weighted Average) = 1 ppm, 10
      mg/m3; STEL (Short Term Exposure Limit) = 2 ppm, 20 mg/m3 (15a).
           A.  ACUTE TOXICITY
               DERMAL:  It did not cause skin sensitization and was
           mildly irritating to guinea pigs.  Rabbits showed no clinical
           signs of toxicity as a result of skin applications of 5000 mg/kg,
           the maximum feasible dose under test conditions.  Autopsy showed no
           gross pathologic changes (15b).
               ORAL:    LD50 = 5200 mg/kg (male rat) (15b).
               INHALATION:  All rats tolerated a 4-hr. exposure at the
           equivalent of 4800 mg/m3 (4.8 mg/L) indicating a low order of
           acute inhalation toxicity.  Higher concentrations were impractical
           under test conditions (15b).
               EYES:    Administration of 10 mg of dry 50% powder, or
           0.1 ml of a 10% suspension in mineral oil, to rabbits' eyes
           produced only a slight, transient conjunctival irritation; there
           was no corneal injury (31j).
           No-effect dietary concentration levels in two-year feeding studies
      are considered to be greater than 250 ppm but less than 1250 ppm for
      rats and 1250 ppm for dogs.  Dietary concentrations of 250 ppm did not
      adversely affect reproduction of rats and rabbits.  There was no
      evidence of teratogenicity or carcinogenicity in these chronic studies
                        IV.  ENVIRONMENTAL  CONSIDERATIONS
           LC50 (96 hr) for mallard ducklings and bobwhite quail 10,000
      mg/l.  LC50 (48 hr) is: for bluegill 71 mg/l; for carp 164 mg/l (62).
           LC50 (48 hours) for bluegill sunfish is 71 ppm
           LC50 (48 hours) for carp is 164 ppm
           LC50 (72 hours) for rainbow trout is 28 ppm
           LC50 (96 hours) for fathead minnows is 182 ppm (31j).
           Half-life of bromacil was approximately 5 to 6 months when 4 lbs
      (active) per acre was applied to the surface of Butlertown silt loam.
      About 90% of the residual activity recovered from the soil was intact
      bromacil (31j).
           Subject to microbial decomposition under moist conditions in soil
           Bromacil is much less subject to adsorption on soil colloids than
      many commercial herbicides.  For example, the amount of bromacil
      adsorbed on Keyport silt loam in equilibrium with 1 ppm in soil
      solution at room temperature is 1.5 ppm compared with 2.6 ppm of
      monuron and 4.0 ppm of diuron.  Bromacil falls in group three of the
      mobility classification suggested by Helling and Turner (1968) (58).
           Microbiological degradation apparently is a mode of disappearance
      from soils.  Soil diphtheroids, Pseudomonas and Penicillium species are
      among the organisms involved (58).
           Tests at elevated temperatures and long exposures to sunlight
      indicate that loss from soil due to volatilization and
      photodecomposition are negligible (58).
           When sterilant rates are applied, activity usually is noted for
      more than one season.  The half-life of 2-C14-labeled bromacil was
      determined to be approximately 5 to 6 months when 4 lb/A were applied
      to the surface of Butlertown silt loam (58).
           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:  Irritant to skin, eyes, and
      respiratory tract (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).
      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
                     (1)  If the victim is unconscious or obtunded and
                          facilties 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
      GENERAL:  Hyvar X-L weed killer is a combustible mixture; keep away
      from heat and open flame (31j).
           Hyvar X:  May be ignited by heat or open flame.  Fine dust
      dispersed in air (particularly in confined spaces) may ignite if
      exposed to high temperature ignition source.  These conditions are
      unlikely to occur in normal, outdoor use of this product (31k).
      EXTINGUISHER TYPE:  On small fire use dry chemical, CO2, foam or water
      spray.  If area is heavily exposed to fire and if conditions permit,
      let fire burn itself out since water may increase the contamination
      hazard.  If conditions do not permit, extinguish with water spray.  If
      conditions permit, cool containers with water if exposed to fire.  Wear
      self-contained breathing apparatus (Hyvar X) (31k).
                                VII.  COMPATIBILITY
           Bromacil formulations are compatible with most herbicides with
      which they might be mixed.  Certain ester formulations of phenoxy
      herbicides may create physical problems with the wettable powder in the
      spray tank.  Water-soluble formulations are not compatible with
      products which markedly reduce pH of spray suspensions (AMS, amitrole,
      etc.).  Weed killers containing soluble calcium salts form precipitates
      when used with the water-soluble formulation (58).
                            VIII.  PROTECTIVE MEASURES
      STORAGE AND HANDLING:  Keep from contact with fertilizers,
      insecticides, fungicides, and seeds.  Keep container closed when not in
      use.  Do not reuse container; bury when empty (31j).
           Do not apply (except as recommended for crop use) or drain or
      flush equipment on or near desirable trees or other plants, or on areas
      where the chemical may be washed or moved into contact with their
      roots.  Do not contaminate domestic waters.  Keep out of reach of
      children (Hyvar X) (31k).
           Store in a cool, dry place.  May irritate eyes, nose, throat, and
      skin.  Avoid breathing dust or spray mist.  Avoid contact with skin,
      eyes, and clothing (56).
                       IX.  PROCEDURES FOR SPILLS AND LEAKS
                                  (800) 424-9300
           Clean up promptly.  Do not flush with water, pick up dry by
      sweeping or other effective means.  If spill area is on ground near
      trees or other valuable plants, remove top 2 inches of soil after
      initial cleanup (31k).
                               X.  LITERATURE CITED
      15a. American Conference of Governmental Industrial Hygienists.  1983.
               TLVs:  threshold limit values for chemical substances and
               physical agents in the work environment with intended changes
               for 1983-84.  Cincinnati, OH.  93 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.
      25.  Morgan, D.P.  1982.  Recognition and management of pesticide
               poisonings, 3rd ed.  U.S. Environmental Protection Agency,
               Washington, DC.  120 pp.
      31j. E. I. du Pont de Nemours and Co., Inc., Biochemicals Department.
               1979.  Technical data sheet:  bromacil.  Wilmington, DE.
      31k. E. I. du Pont de Nemours and Co., Inc., Biochemicals Department.
               1977.  Material safety data sheet for Hyvar X weed killer.
               Wilmington, DE.
      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.