540/FS-89-0
                    United States           Office of Pesticides and Toxic Substances
                    Environmental Protection     Office of Pesticide Programs (TS-766CI
                    Agency             Washington, DC 20460
   vvEPA      Pesticide
                    Fact Sheet
                    Name of Chemical:   Tetrachiorvinphos
                    Reason for Issuance:  Registration Standard
                    Date Issued:         October U, 1988
                    Fact Sheet Number:  184
1.   DESCRIPTION OF CHEMICAL

     Generic Name:  (Z)-2-chloro-l-(2,4,5-trichlorophenyl) vinyl
                   dimethyl phosphate

     Common Name:  Tetrachlorvinphos

     Trade and Other Names: Rabon, Stirofos,  Gardona, Gardcide

     EPA Chemical  (Shaughnessy) Codes: 083701

     Chemical Abstracts Service (CAS)  Number: 22248-79-9  [(Z)-isomer]
                                             22350-76-1  [(E)-isomer]
                                             961-11-5 (mixed isomers)

     Year of Initial Registration:  1966

     Pesticide Type: Insecticde

     Chemical Family:  Organophosphate

     U.S.  and Foreign Producers:  E.I.  Dupont  de Nemours & Co.
                                Fermenta Animal Health Co.

2.   USE PATTERNS AND FORMULATIONS

     Application:  Control of filth or manure flies associated with
     livestock and poultry as a feed additive, in mineral blocks;
     indoor on animal premises, direct animal treatment, garbage dumps.

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     Types and Methods of Application:  Premise treatment by conventional
                                       hydraulic sprayer or low pressure
                                       knapsack; animal treatment by hand
                                       (shaker can, hand duster, grooming
                                       brash,  dust mitt), pressurized spray,
                                       flea dollars,  ear tags,  oral feed add-
                                       itive,  dust bags, and oral mineral block


     Types of Formulations:  Dust, granular, pelleted/tableted, wettable pow-
                             der, wettable powder/dust, impregnated material,
                             emulsifiable concentrate,  ready-to-use and pres-
                             surised liquid.

3.   SCIETdCE FINDINGS

     Summary Science Statement

          Technical tei^rachlorvinphos is not very toxic by the  inhalation
     route of exposure, and does not produce clinical signs of  neurotoxicitv,
     No data are available to assess the toxicity of  tetrachlorvinphos  by the
     acute oral and dermal routes of exposure  and studies  are being required
     in the Standard.  TetjracMorvinphos is not teratogenic in  rabbits  but  the
     effects in rats have not yet been assessed.  Rat teratology data received
     in response to a comprehensive Data Call-In (1984) were not received in
     time to be included in the reviews for this standard.  Available data
     indicate that the potential effects of tetrachlorvinphos on reproduction
     are minimal; the only compound-related effect observed in  the rat  was  an
     inoease in liver size in'the F3b weanlings in the highest  dose tested
     (HOT).   There are no acceptable mutagenicity studies  on tetrachlorvinphos.
   Based on a chronic feeding study in dogs, cholinesterase inhibition  and  reduced
     weight gain are the significant toxic effects resulting from  chronic ex-
     posure to tetrachlorvinphos.

          Based on the Agency's Guidelines for Carcinogen Risk Assessment,  the
     Agency has classified tetrachlorvinphos as a Group C (possible human)
     carcinogen with a cancer potentcy estimate (Q^*) of 3.14 x 10~3
     (ing/kg/day)"1.

          Available data indicate that tetrachlorvinphos is practically
     non-toxic to birds, but is highly toxic to fish and honey bees (contact).
     Available data are insufficient to characterize the environmental  fate
     of tetrachlorvinphos.  Preliminary findings indicate that 14C tetrachlor
     vinphos degrades with a half-life of <8 days in medium loam soil.

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Chemical Characteristics of the Technical

     Physical State:   solid

     Color:   tan to brown

     Odor:   mild chemical

     Molecular Weight and Formula:   366.0;

     Boiling Point:  N/A solid at room temperature

     Vapor Pressure:   no data submitted

     Density:  (buUc density)  50-55 Ib/cu ft

     Solubility in various solvents:   at 0 C:   40  ppm in chloroform,
                                               40  ppm in dichloromethane ,
                                               20  ppm in acetone,
                                                8  ppm in xylene,
                                               .15  ppm in water at 24 C
     Toxicology
    Acute Oral: No available studies

    Acute Dermal:   Nb available studies

    Primary Dermal Irritation:   Nb available studies

    Primary Eve Irritation:   Nb available studies

    Dermal  Sensitization:  Nb available studies

    Itoite Inhalation:   3.61  mg/L      Tox. Category III

    Major routes of exposure:   dermal and inhalation ~   --------

    Delayed neurotoxicity:   negative

    Subchronic toxicity:  normocytic anemia and plasma cholinesterase inhibition

    Qncogenicity:  Group C carcinogen; (mouse) Sys. NOEL= 240 mg/taj/day

                                       (rat)  Sys.  NQEL= 6.25 mgAg/day

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 Chronic Feeding:  (Dog)  Sys. NOEL=  3.13 mg/kg/day
                        Sys. LEL= 50 mg/Tcg/day

 Metabolism:   (dog and rat) conpletely metabolized in both; primarily excreted
              in urine
Teratogenicity:  (Rabbits) Maternal NOEL= 375 mg/Xg
                          Fetotoxic NOEL=150 mg/kg
                          Teratogenic NQEL= >750 mg/kg


Reproduction:   (Rat) NOEL=16.65 mg/kg/day
                     LEL= 50.0 mg/kg/day

Mutagenicity: Nb acceptable studies


Physiologic?! and Biochemjcgi, f?v*raŁteristics

Mechanism of Pesticidal Action: Cholinesterase inhibition following ingestion
                                of tetrachlorvinphos

Metabolism and Persistence
     in Plants and Animals:  Currently, there are no end-use products
                             registered for use on any plant conmodity.  The
                             nature of the residue in animals is not adequately
                             understood.  However, the available animal
                             metabolism data indicate that residues of tetra-
                             chlorvinphos will occur in the tissues of ruminants;
                             and poultry following ingestion of feeds containing
                             tetrachlorvinphos .
                aracteristics
     Available data are  insufficient to characterize the environmental fate
of tetrachlorvinphos.

Ecoloical
Avian acute toxicity: Mallard Duck LD50 > 2,000 mg/kg

Avian dietary toxicity:  Mallard Duck LD50 > 5 ,000mg/kg

Freshwater fish acute toxicity:  Bluegill IŁ5o = 0.53 ppn
                                 Rainbow Trout IŁ50 = 0.43 ppm

Freshwater invertebrate toxicity: No available studies

Marine invertebrate toxicity: Nb available studies

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      4.  THT. FRANCE
      Tolerances have been established for  residues of tetrachlorvinphos'
       in/on a variety of raw agricultural  commodities  (40 CFR 180.252). A
      feed additive regulation has also been established for
      tetracmorvinphos (21 CcR 186.950).   Since there are no currently
      registered products bearing labeling  for use on food crops tolerance
      revocation procedures (40CFR 180.7) will be initiated for apples, field
   .   corn, sweet corn and popcorn, fresh corn forage and fodder, alfalfa,
      cherries, cranberries, peaches,  pears, and tomatoes.  The Agency has
      evaluated the residue and toxicology  data supporting the tolerances on
      animal commodities and has determined that it does not have sufficient
      data to support the currently established tolerances residues of
      tetrachlorvinphos.   Because of the  extensive residue chemistry and
      toxicology data gaps, no significant  new tolerances or new food uses
      will be granted until the Agency has  received data sufficient to
      evaluate the dietary exposure of tetrachlorvinphos.

      There are no Canadian or Mexican tolerances and no Codex Maximum
 Residue Limits (MRLs)  have been established for tetrachlorvinphos residues
 in poultry fat and eggs.   Therefore,  no  compatibility questions exist with
 respect to the Codex MRLs.

       5.  SUMMARY OF REGULATORY POSTTICNS

      The  Agency is not initiating a special review for tetrachlorvinphos at
 this  time.  Although tetracnlorvinphos has been classified as a Group C
 oncogen (possible human) ,  anticipated dietary exposure to humans and the
 associated risk is not high (10-6).

      The  Agency has detemined that based upon currently available data,
 tetrachlorvinphos does not meet the risk criteria (40 CFR 152.170) for
 restricted use,  and thus,  products containing tetrachlorvinphos do not
 warrant restricted use classification at this time.

      The  Agency will reevaluate the safety and efficacy data for various
 formulations of tetrachlorvinphos to  domestic animals  (dogs, cats, hoses) in
 order to  determine if  further regulatory action is warranted.

      The  Agency is requiring protective  clothing for workers or other users
 who mix,  load,  and/or  apply tetrachlorvinphos.

      The Agency is requiring data to  show  the concentration and degradation
 products  of tetrachlorvinphos in fresh manure at the time it is used on land
 as fertilizer.

     The Agency will not grant any tolerances for significant new food uses1
until  sufficient  data  (residue chemistry and toxicology) are submitted for
the Agency to perform  a tolerance reassessment for tetrachlorvinphos.

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     6. TAREf.Tfty; REQUIREMENTS

      All products allowing for outdoor use must bear the fol.lowi.rx-,
environmental hazards statement:

     '"Diis is toxic to fish.  Do not contaminate water when disposing o.
     equipment washwaters."

     The following protective clothing statements muse appear ou CUL_
products allowing for use on livestock, agricultural premises, f.**?
additives: For sprays and dusts:

     "Wear1 long-sleeved shirt and pants; chemical resistant gloves:   s-„
     and socks,"  For ear tags:  "Wear gloves when applying tags ,

     The following statements must appear on all products allowiro ,.
domestic use:

   i' "Wear long-sleeved shirt and pants, shoes and socks.18

     All products allowing for use as a feed additive and/or use on :.- .<•
(droppings) must bear the following statement:

     "Do not use manure/droppings on land where food crops are to t-e or- -*
     during the current growing season."
  7.  SUMVRRY OF DATA GAPS
               DATA
     Product Cnemistry- All

     Environmental Fate- Hydrolysis
                         Photodegradatian (in water)
                         Metabolism Studies
                         Mobility Studies
                         Dissipation Studies  (soil)
                         Dissipation Study (excrement)

     Toxicology- Acute Oral  (rat)
                  Acute Dermal  (rat)
                 - Eye Irritation (rabbit)
                  Dermal Irritation (rabbit)
                  Dermal Sensitization  (guinea pig)
                  Mutagenicity
                  21-Day Dermal
                  Cncogenicity  (rat)
                  Teratology  (rat)
DUE DATE.. From }Jf>""-
    QF
  9-15 Months
  9-27
  9-12 Months
  50 Months

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     Ecological Effects- Acute Toxicity to             9 Months
       Freshwater Invertebrates

     Residue Chemistry- Livestock Metabolism
                        Analytical Methods
                        Stoxage Stability  '            18-24 Months
                        Magnitude of residues
                        in meat, milk,  eggs
8.  CXMaCT PERSON AT EPA
    George T. LaRoccp
    Product Manager (15)
    Insecticide-Rodenticide Branch
    Registration Division (TS-767C)
    Office of Pesticide Programs
    Environmental Protection Agency
    401 M Street, S.  W.
    Washington, D. C.   20460

    Office location and telephone number:  Room 204;  (703)  557-2400

    Crystal Mall t2
    1921 Jefferson Davis Highway
    Arlington, "VA  22202
    (703) 557-2600
    DISCLAIMER:     Tne information in this Pesticide Fact Sheet
    is a summary only and is not to be used to satisfy data
    requirements for pesticide registration and reregistration.
    Ihe complete Registration Standard for the pesticide may be
    obtained from the National Technical Information Service.
    Contact the  Product Manager listed above for further
    information.

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vvEPA
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   Office of Pesticide Program (TS-757C)
   PMSD, Information Services Branch
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