ARS PESTICIDE PROPERTIES DATABASE last updated Jan, 2002


name: BENSULFURON METHYL                          CASRN: 83055-99-6


SELECTED VALUES FOR MODELING PURPOSES (from Hornsby, et al., 1996)

WATER SOLUBILITY (mg/L): 120 (pH7)
FIELD HALF-LIFE (days): 5
SOIL ORGANIC CARBON SORPTION (Koc, mL/g): 370 (pH7)
VAPOR PRESSURE (mm Hg): 2.1 x 10-14
pKa: 5.2


PUBLISHED AND MANUFACTURER VALUES AND SOURCES

molecular formula: C16H18N4O7S
molecular weight : 410.4
physical state   : S
(L=liquid; G=gas; S=solid)
reference: 9ACHB2

_________________________________________________________________________
Key to sources: (M)Manufacturer, (R)eview, (H)andbook, (E)xperiment,
                (C)alculated, (U)nknown, (P)EPA data, (W)auchope

* denotes a selected value where multiple values of a property are listed.
_________________________________________________________________________

-value-            -medium-   -temp-  -pH-   -source-    -reference-


Boiling point(deg C):
       -

Melting point(deg C):
185    -    188                                  M        9DUPON,1999

Decomposition point(deg C):
       -

Heat of vaporization(deg C):

--RATE CONSTANTS--

Hydrolysis (per day):
0.063*                           25     5        M        9DUPON
<0.004*                          25     7        M        9DUPON,1999
<0.004                           25     9        M        9DUPON,1999

Photolysis (per day):
0.0315               SOIL        25     5.8      M        9DUPON,1999
<0.000001            WATER       25     5        M        9DUPON,1999
0.0014               WATER       25     7,9      M        9DUPON,1999
0.0012               WATER       25     9        M        9DUPON,1999

Vapor pressure (mPa):
2.8E-9*                          25              M        9DUPON


Water solubility (ppm):     -temp-    -pH-    -source-    -reference-
80*                           25        7        M        9DUPON
1.1                           25        5        M        9DUPON
880                           25        8        M        9DUPON

Organic solubility (ppm):


Henrys law (Pa m3/mol):
1.04E-9                       25        5        M        9DUPON,1999
1.4E-11*                      25        7        M        9DUPON
1.31E-12                      25        9        M        9DUPON,1999

Octanol/water partitioning (log Kow):
0.8*                          25        7        M        9DUPON
2.2                           25        5        M        9DUPON
-1.0                          25        9        M        9DUPON

Acid dissociation (pKa):
5.2*                                             M        9DUPON


Soil sorption:
soiltype            temp.   Kd     Koc    %om   pH     reference
WOODSTOWN(SNDY LM)   25     1.4    219    1.1   6.6    9DUPON
CECIL(SNDY LM)       25     2.5    205    2.1   6.5    9DUPON
FLANAGAN(SILT)       25     14     561    4.3   5.4    9DUPON
KEYPORT(SILT LM)     25     12     276    7.5   5.2    9DUPON



Field Dissipation halflife(days):
value           test area        pH         source     reference
5                                             M        9DUPON
4               RICE PADDY       7.8(WATER)   M        9DUPON,1999
                WATER(JAPAN)
4               RICE PADDY       7.1(SOIL)    M        9DUPON,1999
                WATER(JAPAN)
3               RICE PADDY       7.0(SOIL)    M        9DUPON,1999
                WATER(CA)
6               RICE PADDY       5.4(SOIL)    M        9DUPON,1999
                WATER(AR)
3               RICE PADDY       6.7(SOIL)    M        9DUPON,1999

Halflife in soil:
Soiltype        aerobic    anaerobic   pH   source     reference
                24*                           M        9DUPON,1999
SILT LM(CA)     ~22**                         M        9DUPON,1999
                ~22***                        M        9DUPON,1999
SANDY LM(JAPAN) ~20**                         M        9DUPON,1999
                ~22***                        M        9DUPON,1999
SILT LM(JAPAN)  ~21**                         M        9DUPON,1999
                ~35***                        M        9DUPON,1999

Comments:
WATER SOLUBILITY HAS A PH VALUE OF 7; OCTANOL WATER=PH7;
SOIL SORPTION KOC=315(205-561)
HALFLIFE = **PHENYL MOIETY
          ***PYRIMIDINE MOIETY