ARS PESTICIDE PROPERTIES last update May 1995


name:METHAMIDOPHOS                             CASRN: 10265-92-6

molecular formula: C2H8NO2PS
molecular weight : 141.13
physical state   : S
(L=liquid; G=gas; S=solid)
reference: 6MILES

_________________________________________________________________________
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):
44.5   -                                         H     9ACHB2,2ND ED.,1987

Decomposition point(deg C):
       -

Heat of vaporization(deg C):



Hydrolysis (per day):
0.002 *                          25     5        M     6MILES
0.025 *                          25     7        M     6MILES
0.215 *                          25     9        M     6MILES

Photolysis (per day):
0.210 *              SOIL        26 OD           M     6MILES
0.0079 *             WATER       9-42 OD         M     6MILES

Vapor pressure (mPa):
106                               0              M     8VALUS
4.27 *                           20              M     6MILES
40                               30              H     9ACHB2,2ND ED.,1987


Water solubility (ppm):       -temp-          -source-   -reference-
MISCIBLE *                       20              M     6MILES
2E+06                            20              H     9ACHB2 7TH ED., 1977

Organic solubility (ppm):
>2.0E+5 * 2-PROPANOL             20              M     6MILES
>2.0E+5 * DICHLOROMETHANE        20              M     6MILES
<1.0E+4 * TOLUENE                20              M     6MILES
<2.5E+4 * DIETHYL ETHER          20              H     9ACHB2, 2ND ED.,1987
<1.0E+4 * KEROSENE               20              H     9ACHB2, 2ND ED.,1987
<1.0E+5 * BENZENE                20              H     9ACHB2, 2ND ED.,1987

Henrys law (Pa m3/mol):
3E-07 *                          20              M     6MILES

Octanol/water partitioning (log Kow):
-.79 *                           20              M     6MILES

Acid dissociation (pKa):


Soil sorption:
soiltype        temp.   Kd      Koc      %om   pH      reference
                                <1 *                   8VALUS

Field Dissipation halflife(days):
value             test area        pH         source   reference
6-15                                            H      9ACHB2 1983 ED.
2-6                                             M      8VALUS
<1           CA(CHUALAR) LMY SND   7.3          M      6MILES
<<1          CA(FRESNO) LMY SND    7.8          M      6MILES
3.5(<1-15) *

Halflife in soil:
Soiltype               aerobic    anaerobic   source   reference
MOORETOWN,N.J. LOAM     4.8                     M      6MILES
FLORIDA SANDY LOAM      6.1                     M      6MILES
LOAMY SAND                           11         M      6MILES       
SANDY LOAM              0.583        4          M      6MILES
                        4 *          7.5 *


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