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alachlor (Lasso) Herbicide Profile 6/85

      CHEMICAL NAME:      2-Chloro-2'-6'-diethyl-N-(methoxymethyl)-acetanilide
      TRADE NAME(S):      Lasso (56)
      FORMULATION(S):     Emulsifiable concentrate (4 pounds/gallon), granules
                          (15%) (56).
      TYPE:               Acetanilide herbicide
      BASIC PRODUCER(S):  Monsanto Agricultural Products Co.
                          800 N. Lindbergh Blvd.
                          St. Louis, MO 63166
      STATUS:             General use.  A Special Review of all pesticide
      products containing the active ingredient alachlor was initiated
      on January 9, 1985.  The EPA has determined that alachlor produces
      tumors in laboratory rats and mice and that humans can be exposed
      to alachlor through consumption of treated crops, consumption of
      water, or contact during handling and use as a pesticide.
      As a result of the the Special Review and the reregistration process,
      the following label changes have been made:
        -- Lasso will no longer be approved for use with potato crops or
           in aerial applications.
        -- Use rates of 6 to 8 pounds per acre for soybeans, formerly
           recommended for certain unusual soil conditions, have also
           been removed from the label.
        -- The new label requires goggles or face shield, rubber gloves,
           long trousers, long sleeved shirt or jacket of tightly woven
           material along with boots high enough to cover ankles when
           transferring and mixing, and when adjusting, repairing or
           cleaning equipment.  Wear rubber boots when pouring from
           open containers or when re-entry is made into fields where the
           product has been applied thriugh center pivot irrigation and the
           field is still wet.
           The new label also includes new instructions on mixing, spraying
           and handling.
        -- Because of EPA concern over groundwater in general and the low
           level finding of alachlor in water, precautionary steps against
           potential water contamination are described in new label statements.
        -- The new label encourages growers to obtain information on careful
           handling and use practices.
      PRINCIPAL USES:  For controlling many annual grasses and certain
      broadleaf weeds in soybeans, corn, peanuts, dry beans, sunflowers,
      milo.  Leaves no residue in soil to carry over to the next
      year.  Can be broadcast, banded or applied by ground
      equipment in water or sprayable fluid fertilizers, or impregnated on
      dry bulk fertilizer, preplant incorporated or preemergence as directed
      on the label (56).
                                   I.  EFFICACY
           To be developed.
                             II.  PHYSICAL PROPERTIES
      MOLECULAR FORMULA:  C14 H20 Cl NO2 (62)
      MOLECULAR WEIGHT:   269.8 (62)
      PHYSICAL STATE:     Cream-colored solid (pure compound) (62)
      ODOR:               Odorless (pure chemical) (58)
      MELTING POINT:      39-41.5 C (pure compound) (62); 39.5-41.5 C
                          (technical) (56).
      BOILING POINT:      100 C at 0.02 mmHg, 135 C at 0.3 mmHg (pure
                          chemical) (58).
      DECOMPOSITION TEMPERATURE:  105 C (pure compound) (62)
      VAPOR PRESSURE:     2.2 x 10-5 mmHg at 25 C, 0.02 mmHg at 100 C (pure
                          chemical) (58).
      SOLUBILITY:         242 mg/l water at 25 C (pure compound) (62)
                          III.  HEALTH HAZARD INFORMATION
           A.  ACUTE TOXICITY
               DERMAL:  a. Technical alachlor
                             Rabbit acute dermal LD50 - 13,300 mg/kg
                             Rabbit skin irritation - 1.9 on a scale of 8.0,
                               slightly irritating
                        b. Lasso
                             Rabbit acute dermal LD50 - 7800 mg/kg
                             Rabbit skin irritation - 4.8 on a scale of 8.0,
                               moderately irritating
                        c. Lasso EC
                             Rabbit acute dermal LD50 - 8,000 mg/kg
                             Rabbit skin irritation - 3.2 on a scale of 8.0,
                               moderately irritating
                        d. Lasso II
                             Rabbit acute dermal LD50 - 16,000 mg/kg,
                               practically non-toxic by single dermal
                             Rabbit skin irritation - 1.2 on a scale of 8.0,
                               slightly irritating (58)
               ORAL:    a. Technical alachlor
                             Rat acute oral LD50 - 930 mg/kg
                        b. Lasso
                             Rat acute oral LD50 - 2000 mg/kg
                        c. Lasso EC
                             Rat acute oral LD50 - 1000 mg/kg
                        d. Lasso II
                             Rat acute oral LD50 - 5800 mg/kg (58)
               INHALATION:  LC50 = >32 mg/l air for 1 hr - no adverse effects
                            noted during 14 days of observation (rat, Lasso
                            15G) (54).
               EYES:    a. Technical alachlor
                             Rabbit eye irritation - 0.4 on a scale of 110.0,
                        b. Lasso
                             Rabbit eye irritation - 44.6 on a scale of 110.0,
                               moderately irritating
                        c. Lasso EC
                             Rabbit eye irritation - 41.0 on a scale of 110.0,
                               moderately irritating
                        d. Lasso II
                             Rabbit eye irritation - 21.6 on a scale of 110.0,
                               slightly irritating (58)
           Growth patterns were normal with technical fed to rats and beagle
      dogs at levels of 20, 200, and 2,000 ppm for a 90-day period.  Animals
      fed at the 2,000 ppm level exhibited some growth depression, and
      weights of male dogs were below normal (54).
                        IV.  ENVIRONMENTAL  CONSIDERATIONS
           a. Wildlife
              Eight-Day Feeding LC50 - 10-15 day old mallard ducklings -
                                         greater than 5000 ppm
                                       10-15 day old bobwhite quail chicks -
                                         greater than 5,000 ppm
           b. Aquatic organisms - technical
              96 hour LC50 in Rainbow Trout - 1.8 mg/l
              96 hour LC50 in Bluegill Sunfish - 2.8 mg/l
              48 hour EC50 in Daphnia magna - 10 mg/l
              Lasso EC
              96 hour LC50 Rainbow Trout - 4.2 mg/l
              96 hour LC50 Bluegill Sunfish - 6.4 mg/l
              48 hour EC50 Daphnia magna - 35 mg/l (58)
      Behavior In or On Soils
      1.  Adsorption and leaching characteristics in basic soil types:
            Adsorbed by soil colloids.
      2.  Microbial breakdown:  Main method of degradation.
      3.  Loss from photodecomposition and/or volatilization:  Low.
      4.  Resultant average persistence of recommended rates:  6 to 10 weeks
            but may vary depending on soil type and climatic conditions (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:  Mild irritant (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
                          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)  ASPIRTE 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
           Combustible (58).
                                VII.  COMPATIBILITY
           Compatible with water of 1,000 ppm hardness or less; usually
      compatible with sprayable fluid fertilizers.  No corrosion to No. 316
      and No. 304 stainless steel, aluminum and heresite.  Corrosive to steel
      and black iron (58).
                             VIII.  PROTECTIVE MEASURES
      STORAGE AND HANDLING:  Do not store near heat or open flame.  Avoid
      contact with eyes and skin.  Wash thoroughly after handling (58).
           Store above 32 F to keep product in solution.  Below 32 F
      crystals may form and settle to the bottom.  If crystals form, place
      in a warm room and roll and shake container frequently for several
      days (56).
      PROTECTIVE CLOTHING:  Wear goggles or face shield and rubber gloves
      in transferring and mixing and when adjusting, repairing, or cleaning
      equipment (56).
                       IX.  PROCEDURES FOR SPILLS AND LEAKS
                                  (800) 424-9300
                               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.
      54.  Weed Science Society of America, Herbicide Handbook Committee.
               1979.  Herbicide handbook of the weed science society
               of America, 4th ed.  Weed Science Society of America,
               Champaign, IL.  479 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.