ARS PESTICIDE PROPERTIES last update May 1995


name:METHYL PARATHION                          CASRN: 298-00-0

molecular formula: C8H10NO5PS
molecular weight : 263.21
physical state   : S
(L=liquid; G=gas; S=solid)
reference: 9ACHB2

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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):
154    -           1.0mmHg                        H       9ACHB2

Melting point(deg C):
35     -     36                                   H       9ACHB2

Decomposition point(deg C):
       -

Heat of vaporization(deg C):


--RATE CONSTANTS--

Hydrolysis (per day):
0.010                           25      5       H     9PME10
0.017                           25      7       H     9PME10
0.021                           25      9       H     9PME10

Photolysis (per day):

Vapor pressure (mPa):
2.3                             25              E     JAFCAU 27:273-278,1979
5.3                             30              E     JAFCAU 27:273-278,1979
1.3                             20              E     PSSCBG 4:137-147,1973
0.2*                            20              H     9PME10
0.41                            25              H     9PME10

Water solubility (ppm):       -temp-        -source- -reference-
55-60                           25              H     9ACHB2 1983 ED.
55*                             20              H     9PME10

Organic solubility (ppm):

Henrys law (Pa m3/mol):
9.57E-4*                        20              H     9PME10

Octanol/water partitioning (log Kow):

Acid dissociation (pKa):



Soil sorption:
soiltype        temp.   Kd      Koc      %om   pH     reference
                                5100                 JEVQAA 16:422-428,1987
                                                     9EINSP PP.23-67
                                                     SCSFAD 44:1-8,1985
                                424                  WATRAG 13:375-380,1979
                                14000                8GLEAM
                                560                  8CREAM
                                7330                 8INSFO
                                7079                 8AGMAW
                                9800                 8SWAMD
                                6300*

Field Dissipation halflife(days):
value        test area        pH          source     reference
15                                           E       JEVQAA 16:422-428,1987
                                             C       SCSFAD 44:1-8,1985
5                                            C       8GLEAM
4-15                                         R       9EINSP PP.23-67
4                                            R       8INSFO
3-11                                         R       9KAUGW
1                                            C       SCSFAD 44:1-8,1985
30                                           R       8FULLE
10(1-30)*

Halflife in soil:
Soiltype          aerobic      anaerobic   source    reference


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