ARS PESTICIDE PROPERTIES DATABASE last updated May 1995 name: DSMA CASRN: 144-21-8 molecular formula: CH3AsNa2O3 molecular weight: 183.9 physical state: S (L=liquid; G=gas; S=solid) reference: 9PMED9 __________________________________________________________________________ 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): 133 - 139 H 9PME10 Decomposition point (deg C): Heat of vaporization (deg C): --RATE CONSTANTS-- Hydrolysis (per day): Photolysis (per day): Vapor pressure (mPa): 0 W Water solubility (ppm): 279000 20 H 9PMED9 254000 C ESTHAG 14: 553-556 (1980) 256000 20-25 E ADCSAJ 111: 55-120 (1972) Organic solubility (ppm): SOLUBLE IN METHANOL, H 9PME10 INSOLUBLE OTHER ORGANIC SOLVS. Henrys law (Pa m3/mol): Octanol/water partitioning (log Kow): Acid dissociation (pKa): Soil sorption: soiltype temp. Kd Koc %om pH reference -------- ----- -- --- --- -- --------- 770 ESTHAG 14: 553-556 (1980) 393 6.1 6WEEDS 15: 299-304 (1967) 822 6.2 6WEEDS 15: 299-304 (1967) 110 6.0 6WEEDS 15: 299-304 (1967) 755 5.3 6WEEDS 15: 299-304 (1967) 600* Field dissipation halflife(days): value test area pH source reference ----- --------- -- ------ --------- 180 W Halflife in soil: soiltype aerobic anaerobic source reference -------- ------- --------- ------ --------- Comments: DSMA = METHYLARSONIC ACID DISODIUM SALT