MSMA

Favorites

Chemical Identification | General Product Information | Physical & Safety Data

Chemical Identification

Common Name

MSMA

中文通用名

甲基砷酸钠

IUPAC

sodium hydrogen methylarsonate

CAS

monosodium methylarsonate

CAS No.

[2163-80-6]

Molecular Formula

CH₄AsNaO₃

Molecular Structure

General Product Information

Category

Herbicides > Arsenical herbicides

Activity

Herbicide

Premix

Liquid, liquid plus surfactants, soluble granules.
Premix Parters: cypermethrin; malathion; methyl eugenol methylene chloride;

Physical & Safety Data

Physical Properties

Molecular weight:162.0; Physical form:Colourless crystals (hydrate); (, clear light yellow liquid). Density:1.535 g/ml (25 °C); Composition:MSMA forms a sesquihydrate. Tech. material is 51% MSMA. Melting point:113-116 °C (sesquihydrate); Vapour pressure:1 × 10-2 (25 °C); Partition coefficient(n-octanol and water):logP <0; pKa:9.02; Solubility:In water 1.4 / (anhydrous salt) (20 °C). Soluble in methanol; insoluble in most organic solvents.; Stability:Stable to hydrolysis. Decomposed by strong oxidising and reducing agents.; Tech: clear light yellow liquid; practically odorless. Boiling point >100°C.

Toxicology

Oral:Acute oral 50 for young albino rats 900 /. Percutaneous:Mild irritant to skin and eyes (rabbits). Inhalation:50 (4 h) >20 /l.

Environmental Profile

Ecotoxicology:
Algae:(for 51% MSMA) 50 (5 d) for Selenastrum 7.6 /l.Bees:50 68 mg/bee; 36 mg/bee.Birds:50 for quail 425.2 g/kg. Dietary 50 (5 d) for quail 1667, mallard ducks >2866 .Daphnia:50 (48 h) 77.5 /l.Fish:50 (96 h) for bluegill sunfish >51, trout >167 /l. for bluegill sunfish 93.2, trout 167 /l.Other aquatic spp.:(for 51% MSMA) EC₂₅ (14 d) for Lemna gibba 107.3 /l; 50 (14 d) 145.9 /l.

Environmental fate:
Soil:Terrestrial dissipation, 50 55 d, 50 for cacodylic acid (primary metabolite) 88 d. MSMA and cacodylic acid are found primarily in upper 6 inches of soil. oc 250 (sandy

Transport Information

Signal Word:CAUTION; Hazard Class:III(Slightly hazardous)