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Physical/Chemical Parameters:Fenvalerate

Fenvalerate

      PESTICIDE NAME: Fenvalerate
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      Trade name(s): Pydrin, Ectrin
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      Manufacturer(s): Shell Chemical Co., Division of Shell Oil
      ________________
                       P.O. Box 3871
                       Houston, TX. 77001
                       SDS Biotech Corp.
                       7528 Auburn Rd.
                       P.O. Box 348
                       Painesville, OH.  44077

      I.  Basic information
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          A. Molecular structure: C25H22ClNO3
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          B. Chemical name: cyano(3-phenoxyphenyl)methyl 4-chloro-
             _____________
      alpha(1-methylethyl)benzeneacetate

          C. Derivatives: CONH2-Pydrin; 4-OH-Pydrin
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          D. Molecular weight: 419.9 g/mole
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           E. Solubility in water: very low solubility
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           F. Common physical appearance: clear, yellow, viscous liquid
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           G. Oral LD50(rat): 451 mg/kg
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           H. Pesticide classification: synthetic pyrethroid insecticide
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           I. Restricted use list (N.Y.): yes
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              EPA priority pesticide list: no
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           J. Crop use: apple, pear, peach, cabbage, cauliflower, broccoli,
      Brussels sprouts, potato, sweet corn, tomato

      II.  Text
           ____
           Fenvalerate is a non-leaching, non-volatile readily degradable
      synthetic pyrethroid insecticide which is similar in behavior to
      permethrin but remains in the soil for a longer time than permethrin.
      It is used on a variety of fruits and vegetables in New York state and
      is not on the restricted use list.  The scientific literature contains
      a moderate amount of information on fenvalerate in soils.  The
      half-life of fenvalerate varies from 6 weeks to 60 days depending upon
      the soil type.

      III.  Soils information
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            A. Degradation and transformation
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           The degradation of fenvalerate is slower in sterile than
      non-sterile soil thus indicating the primary path of decomposition is
      biological rather than chemical(2,5,7).  Degradation is also affected
      by treatment and moisture levels and rates are not constant over
      time(1).  Disappearance is more rapid in mineral than organic
      soil(1,2).  The percent fenvalerate left in mineral and organic sterile
      and non-sterile soils 8wks after application has been reported as 91%
      in mineral sterile soil, 12% in mineral non-sterile, 100% in organic
      sterile, and 58% in organic non-sterile(2).  A second study reported
      losses of 78% of the applied fenvalerate in mineral non-sterile soil at
      2wks and a loss of only 21% in organic non-sterile soil in 10wks(1).
      From this it was concluded that multiple applications of fenvalerate on
      a muck soil could result in accumulation of the pesticide.
           The half-life of fenvalerate varies according to the soil being
      tested.  Values reported are 6wks in clay loam with 15.1% remaining
      after 16wks and 11.3% remaining after 45wks(4); half-life of 2mo in
      mineral and organic soils(1); half-life in aerobic sandy loam equal to
      60d(5); loss of 50% of initial application at 9wks decreasing to 12% at
      48wks and the fenvalerate at this point being a combination of 4
      isomers (3); and half-life light clay = 2d, sandy clay loam = 6d and
      sandy loam = 18d(6). This last study examined the relationship between
      half-life of fenvalerate and latitude finding a fall/winter increase in
      half-life where latitude >40deg N and no difference in spring/summer.
      At latitudes <20deg N, half-lives remained constant at all times of the
      year(6).  Another researcher reports a rapid decrease in fenvalerate
      applied to silt loam soil in the spring with a slowing of degradation
      in the fall.  This study also reported virtually no carry-over from
      year to year and that more fenvalerate was recovered from cultivated
      soils than from fallow soils(9).  In a subtropical soil, the pesticide
      was applied biweekly for 2yrs with no accumulation until 6mo after
      initial application and 4% recovery at the end of 2yrs(10).
           The reaction products of fenvalerate are CONH2-Pydrin and
      4-OH-Pydrin with eventual decomposition to CO2.  The reaction products
      are not persistent in soil(7).
           The tables below present data concerning degradation and
      transformation of fenvalerate in soil. The reference is given in
      parentheses at the end of each title.

      Percent fenvalerate remaining in two soils under two cultivation
      regimes(1)

                 Incorporated  Fenvalerate     Surface Fenvalerate(1)
                 _________________________     ______________________
       Time(mo)       Sand      Muck               Sand   Muck
       ________       ____      ____               ____   ____
          0.5          89%      100%                71%     53%
          1            67        56                 31      49
          2            22        28                 11      26
          3            33        29                  6      28
          4            11        57                  3      29
          5           <11        25                 <3      29
          6                      25                         15
         12                      32
         18                      17
         28                       7
      (values for top 1/3 of 15cm core)
      ***********************************************************************

      Percent of original fenvalerate application remaining in soil under
      different initial concentration and moisture regimes(1)
                         Percent application remaining in soil
                     __________________________________________________
          Time (mo)        0.5ppm                 10ppm
          _________  ___________________________________________________
                     0.5%mois.     5%mois.     0.5%mois.    5%mois.
                     _________     ______      _________    _______
           0.5          46           38         74          98
          1            29           23         49          63
          2            15           13         26          45
          3             6            8         14          29
          4             4           10         10          25
          5             2            4          6          15
          6             2            4          3          29
      ***********************************************************************

      Degradation rate constants for fenvalerate under differing
      concentration and moisture regimes(1)

      Laboratory Experiments         Rate a(mo-1)
      ___________________________________________________
       Conc(ppm)  Mois(%)       Overall    0-1mo.   1-end
      ___________________________________________________
         0.5       0.5           0.658     1.24    0.566
         0.5       5.0           0.475     1.47    0.344
        10.0       0.5           0.567     0.713   0.534
        10.0       5.0           0.394     0.463   0.376

      Field Experiments
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       Sand Incor.               0.529     0.410   0.499
       Sand Surf.                0.897     1.18    0.760
       Muck Incor.               0.075     0.580   0.106
       Muck Surf.                0.229     0.720   0.158
      ***********************************************************************

      Percent fenvalerate or specie in different soils under light or dark
      conditions(6)

      %Fenvalerate remaining(extractable):
      ______________________________________
         Time  light clay       sandy loam           sandy clay loam
         ____  __________       __________           _______________
               sun   dark       sun   dark           sun      dark
               ___   ____       ___   ____           ___      ____
          3d  22.2   86.0      67.2    90.8           60.4    88.2
         10d  12.3   63.6      48.0    85.9           36.6    69.3
      % CONH2-Fen(extractable):
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          3d  28.4    3.1       4.5     0.8           13.9     2.6
         10d  25.7   17.5       7.9     3.3           22.4     9.9
      %bound fen:
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          3d  39.1    3.3       8.1     1.6            6.0     1.6
         10d  47.5    6.9      12.8     2.4            9.5     2.7
      ***********************************************************************

           B.  Adsorption and transport
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           Fenvalerate is reported to move very little in all types of
      soils(1,4,5,7).  One study found the fenvalerate concentration to be
      6-15times higher in the top than in the middle third of a soil
      core(1).  Another researcher reported 90% recovery of fenvalerate in
      the 0-15cm layer with 10% at 15-25cm(9).  In clay loam, persistence was
      found to occur mainly in the 0-2.5cm layer with <0.5% applied
      fenvalerate found in the 2.5-5.0cm layer.  This study also reported
      very little lateral surface movement(4).  The desorption of fenvalerate
      is dependent upon the amount of clay and organic matter present.  An
      equivalent of 20 acre-inches of water resulted in 1-3% leaching with
      most fenvalerate staying in the top 3cm(5).
           The table below presents data concerning adsorption and transport
      of fenvalerate in soil.  The reference is given in parentheses at the
      end of the title.

      Fenvalerate concentration (ppm) with depth after 5 pesticide
      applications at 6mo intervals(9)
      depth          cultivated soil             fallow soil   (PPM)
      ______________________________________________________________________
      0-15 cm        0.015_0.004                 0.011_0.006
      15-25          0.001_0.002                 0.001_0.001
      25-35             TRACE                       TRACE
      ***********************************************************************

      IV. References (*denotes key reference)
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      *1.Chapman, R.A., and C.R. Harris. 1981.
           J.Environ.Sci.Health.B16(5). 605-15.
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       2.Chapman, R.A., C.M. Tu, C.R. Harris, and C. Cole. 1981.
           Bull.Environ.Contam.Toxicol. 26. 513-19.
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       3.Harris, C.R., R.A. Chapman, and Carol Harris. 1981. Can.Entomol.
            ___________________________                                                  
       4.Talekar, N.S., H.T. Kao, and J. S. Chen.  1983.  J.Econ. Ento.  76(4) 711-16.