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oryzalin (Surflan, Ryzelan) Herbicide Profile 2/85

                                      oryzalin
      CHEMICAL NAME:      3,5-Dinitro-N4,N4-dipropylsulfanilamide (56)
      TRADE NAME(S):      Surflan, Ryzelan, Dirimal (56)
      FORMULATION(S):     Wettable powder (75 WP) and 4 pounds/gallon aqueous
                          suspension (56).
      TYPE:               Dinitrotoluidine herbicide
      BASIC PRODUCER(S):  Elanco Products Co.
                          Div. of Eli Lilly and Co.
                          740 South Alabama St.
                          Indianappolis, IN 46285
      STATUS:             General use
      PRINCIPAL USES:  For control of annual grasses and broadleaf weeds in
      conventional and no-till soybeans, cotton (Texas only), bearing and
      nonbearing fruit trees, nut trees, vineyards, and established
      ornamentals (56).
      APPLICATION METHOD(S):  Oryzalin should be applied as a preemergence
      spray to the soil surface.  In soybeans, if no rain occurs for 7 to 10
      days after application, oryzalin can be shallowly incorporated without
      reducing its herbicidal activity.  For use on crops in areas of seasonal
      rainfall, for example in fruit and nut crops, vines, ornamentals and
      noncropland areas, applications of oryzalin should be made during the
      rainy season so that rainfall will move it into the weed germination
      zone (58).
                                   I.  EFFICACY
           At recommended rates, oryzalin is effective for controlling many
      annual grass and broadleaf weeds such as:  barnyardgrass (Echinochloa
      crusgalli), annual bluegrass (Poa annua), brachiaria (Brachiaria sp.),
      browntop panicum (Panicum fasciculatum), crabgrasses (Digitaria sp.),
      crowfootgrass (Dactyloctenium aegyptium), Southwestern cupgrass
      (Eriochloa gracilis), fall panicum (Panicum dichotomiflarum), foxtails
      (Setaria sp.), goosegrass (Eleusine indica), seedling johnsongrass
      (Sorghum halepense), wild oat (Avena fatua), Texas panicum (Panicum
      texanum), carpetweed (Mollugo verticillata), common purslane (Portulaca
      oleracea), Florida purslane (Richardia scabra), lambsquarters
      (Chenopodium album), pigweeds (Amaranthus sp.), chickweed (Stellaria
      media), and prostrate spurge (Euphorbia supina) (58).
           Season-long control may be expected.  Sometimes initial grass
      control is weak but this can be overcome with a light soil cultivation.
      Partial control of velvetleaf, smartweed, spurge, nightshade, morning
      glory, teaweed and ragweed has been obtained.  Being used with other
      herbicides to increase the weed spectrum (8b).
                             II.  PHYSICAL PROPERTIES
      MOLECULAR FORMULA:  C12 H18 N4 O6 S (62)
      MOLECULAR WEIGHT:   346.4 (62)
      PHYSICAL STATE:     Yellow-orange crystalline solid (pure compound) (58);
                          yellow-orange crystalline solid (technical grade)
                          (62).
      ODOR:               No appreciable odor (pure compound) (58)
      MELTING POINT:      141-142 C (pure compound) (58); 141-142 C (technical
                          grade) (62).
      VAPOR PRESSURE:     <1 x 10-7 mmHg at 30 C (pure compound) (58)
      SOLUBILITY:         2.4 mg/l water at 25 C (technical grade) (62)
                          III.  HEALTH HAZARD INFORMATION
      OSHA STANDARD:  NA
      NIOSH RECOMMENDED LIMIT:  NA
      ACGIH RECOMMENDED LIMIT:  NA
      TOXICOLOGY
           A.  ACUTE TOXICITY
               DERMAL:  The application of 2g of Surflan 75 W per kg of body
      weight to the shaved and abraded backs of rabbits for 24 hours caused
      only slight irritation which cleared rapidly. No other signs of
      toxicity were observed.  No local irritation or systemic toxicity was
      observed when 2 ml of undiluted Surflan AS per kg of body weight were
      applied to the shaved and abraded backs of rabbits for 24 hours (58).
               ORAL:  LD50 = >10,000 mg tech./kg (rat, gerbil); 1000 mg/kg
                        (cat, chicken); >1000 mg/kg (dog) (62).
                      Rats were given a single oral dose of Surflan 75W and
                        observed for 14 days.  This treatment resulted in an
                        LD50 of greater than 10 g per kg of body weight (58).
                      No deaths occurred when rats were given a single oral
                        dose of 2 ml of undiluted Surflan AS per kg of body
                        weight (58).
               INHALATION:  Rats were exposed to 3.56 mg of Surflan 75 W, as
      a mist, per liter of air for one hour and observed for 14 days.  This
      treatment caused only minor effects which cleared within 24 hours.
      Rats were exposed to 5.7 microliters of Surflan AS (as a mist) per
      liter for one hour and observed for 14 days.  This treatment caused no
      adverse effects (58).
               EYES:  Slight irritation, which cleared within 7 days, occurred
      when rabbits were treated in one eye with 21 mg of Surflan 75W.  In
      rabbits the instillation of 0.1 ml per eye of undiuted Surfan AS
      produced no irritation (58).
           B.  SUBACUTE AND CHRONIC TOXICITY:
           In 2-yr feeding trials NEL for rats was 300 mg/kg diet (62).
           Chronic oral exposure of rats and mice to large doses of technical
      oryzalin for one year was well tolerated with no indication of
      cumulative toxicity or serious adverse effects.  Daily oral doses of
      18.75 mg of oryzalin per kg of body weight administered to dogs for
      three months were well tolerated with no toxic effects.  Oryzalin fed
      as a large component of the diet to pregnant rats during the period of
      organogenesis and early fetal development resulted in no adverse
      effects on either the dams or their progeny (58).
                        IV.  ENVIRONMENTAL  CONSIDERATIONS
            The LC50 (96 hr) for goldfish fingerlings is >1.4 mg/l (62).
            Laboratory and field studies indicate no undue hazard to fish
      from oryzalin added to water at recommended rates and above (58).
      Behavior In Or On Soils
      1.  Adsorption and leaching characteristics in several soil types:
            Oryzalin leaches to a limited extent under natural rainfall
            conditions.  Organic matter and clay content of the soil
            influence the application rate for herbicidal activity.
      2.  Microbial breakdown:  Microorganisms are believed to play a role
            in the degradation and disappearance of oryzalin from soil.  No
            specific soil organism has been identified as responsible for the
            degradation.
      3.  Loss from photodecomposition and/or volatilization:
            Photodecomposition of oryzalin has been demonstrated in
            laboratory studies.  Volatilization from soil surfaces is minimal
            and does not reduce the herbicidal effectiveness of oryzalin as a
            soil treatment.
      4.  Resultant average persistence at recommended rates:  Field
            studies with 14C oryzalin have indicated its rapid
            biodegradability.  Oryzalin applied at the recommended rate has
            not caused injury to succeeding crops under warm, moist soil
            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:  Slightly to moderately irritating
      to skin, eyes, and mucous membranes.  These agents do not uncouple
      oxidative phosphorylation (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:
      A.    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.
      B.    Activated Charcoal - administer 30-50 gm as a slurry in tap water
            after vomiting stops.
      C.    Sodium or Magnesium Sulfate, 0.25 gm/kg in tap water, as a
            cathartic (25).
           EYE CONTACT:  Flush contaminated eyes with copious amounts of
      fresh water for 15 minutes (25).
      NOTES TO PHYSICIAN:
      1.   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 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.
      2.   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.
      3.   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 a flammable solid.  For the formulated
      wettable powder, use ordinary precautions for handling dust or wettable
      powder formulations (58).
                                VII.  COMPATIBILITY
           Compatible with most other wettable powder formulations and
      fertilizers if not highly alkaline.  Oryzalin is not significantly
      influenced in its sprayability by water hardness.  Oryzalin is not
      corrosive (58).
                            VIII.  PROTECTIVE MEASURES
      STORAGE AND HANDLING:  Harmful if swallowed or absorbed through the
      skin.  Avoid contact with skin, eyes or clothing.  In case of contact,
      flush with water.  Do not contaminate foodstuffs or feeds.  Direct
      contamination of any body of water with the wettable powder may kill
      fish.  Do not contaminate any body of water by direct application,
      cleaning of equipment or disposal of wastes.  The shelf life of these
      formulations is more than 2 years (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
       8b. Thomson, W.T.  1981.  Agricultural chemicals - book 2:
               herbicides.  Revised ed.  Thomson Publications, Fresno, CA.
               274 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.
      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.
      2/21/85