ARS PESTICIDE PROPERTIES last update May 1995 name:METRIBUZIN CASRN: 21087-64-9 molecular formula: C8H14N4OS molecular weight : 214.29 physical state : S (L=liquid; G=gas; S=solid) reference: 9MOBAY _________________________________________________________________________ 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): 125.5 - 126.5 H 9ACHB2,2ND ED.,1987 Decomposition point(deg C): - Heat of vaporization(deg C): --RATE CONSTANTS-- Hydrolysis (per day): STABLE* 25 5-9 M 6MILES Photolysis (per day): 0.28 SOIL OD M 6MILES 0.05* SOIL OD M 6MILES 3.83* WATER OD M 6MILES Vapor pressure (mPa): <1.3 20 H 8HERBH 0.017 20 M 6MILES 26.7 60 H 9HERBH 0.017* 20 Water solubility (ppm): -temp- -source- -reference- 1000* 20 1220 20 H 9HERBH H 9ACHB2 1983 ED. 1.0E+03 20 M 6MILES 1.2E+03 20 H 9ACHB2,2ND ED.,1987 Organic solubility (ppm): 7.7E+4* 2-PROPANOL 20 M 6MILES 3.4E+5* DICHLOROMETHANE 20 M 6MILES 8.7E+4* TOLUENE 20 M 6MILES 1.8E+6* DIMETHYLFORMAMIDE 20 H 9ACHB2,2ND ED.,1987 1.0E+6* CYCLOHEXANONE 20 H 9ACHB2,2ND ED.,1987 8.5E+5* CHLOROFORM 20 H 9ACHB2,2ND ED.,1987 8.2E+5* ACETONE 20 H 9ACHB2,2ND ED.,1987 4.5E+5* METHANOL 20 H 9ACHB2,2ND ED.,1987 2.2E+5* BENZENE 20 H 9ACHB2,2ND ED.,1987 1.9E+5* ETHANOL 20 H 9ACHB2,2ND ED.,1987 9.0E+4* XYLENE 20 H 9ACHB2,2ND ED.,1987 1.5E+5* N-BUTANOL 20 H 9ACHB2,2ND ED.,1987 Henrys law (Pa m3/mol): 3.55E-06* 20 M 6MILES Octanol/water partitioning (log Kow): 1.70 E CMSHAF, 13(2):276,1984 1.60* 20 M 6MILES Acid dissociation (pKa): 1.00* E WEESA6, 30(6):631,1982 Soil sorption: soiltype temp. Kd Koc %om pH source reference 95 R EESADV, 4:30,1980 88 R EESADV, 4:30,1980 24 E JEVQAA 16:422-428,1987 95 R EESADV 88 R EESADV 95 C 8GLEAM 9 E JAFCAU 29:1050-1059,1981 SAND 25 0.246 46.7** 1.0 4.3 M 6MILES SANDY LOAM 25 0.0182 3.14** 1.1 6.6 M 6MILES SILT LOAM 25 0.221 14.5** 2.9 5.9 M 6MILES CLAY LOAM 25 0.196 17.0** 2.2 6.4 M 6MILES 52* Field Dissipation halflife(days): value test area pH %OM source reference 30 H 9ACHB2 1983 ED. 30-60 H 9HERBH 37 E JEVQAA 16:422-428,1987 24 C 8GLEAM 35-65 P 8EPAGR 128 CA(CHUALAR)LMY SND 7.3 M 6MILES 39.5 CA(FRESNO)LMY SND 7.8 M 6MILES 47(23-128)* Halflife in soil: Soiltype aerobic anaerobic source reference SANDY LOAM 172* 439* M 6MILES Comments: SOIL SORPTION KOC VALUES WITH A DOUBLE ASTERISK WERE CALCULATED USING A CONVERSION FACTOR OF 1.9(%OM=1.9%OC) RATHER THAN 1.72. SELECTED SOIL SORPTION KOC VALUE=52(3-95)