128-04-1

Preparation

Sodium dimethyldithiocarbamate is prepared by combining dimethylamine with carbon disulfide in a solution of sodium hydroxide, forming the water-soluble dithiocarbamate salt.

Air & Water Reactions

Slowly decomposes in aqueous solution to form carbon disulfide and methylamine or other amines. Such decompositions are accelerated by acids.

Reactivity Profile

Flammable gases are generated by the combination with aldehydes, nitrides, and hydrides. Incompatible with acids, peroxides, and acid halides.

Health Hazard

ACUTE/CHRONIC HAZARDS: When heated to decomposition it emits very toxic fumes.

Fire Hazard

Flash point data for Sodium dimethyldithiocarbamate are not available. Sodium dimethyldithiocarbamate is probably not flammable.

Safety Profile

Moderately toxic by ingestion and intraperitoneal routes. Mutation data reported. When heated to decomposition it emits very toxic fumes of NOx, SOx, and Na2O. See also CARBAMATES.

Potential Exposure

The slow release of poisonous gases from hydrolysis of many thio and dithiocarbamates requires the use of respirators during handling. Used as an antimicrobial/fungicidal agent in paints, water treatment; a registered biocide for cutting oils and aqueous systems in industries such as leather tanning and paper manufacturing. Used in the rubber industry as a vulcanization accelerator for making synthetic and natural rubbers (i.e., butadiene rubber, latex). Used as a fungicide on melons (tolerance set as 25 ppm). Also used as an indirect food additive for use only as a component of adhesives.

Environmental Fate

Routes and Pathways and Relevant Physicochemical Properties The estimated pKa of SDMC is 5.4, indicating that this compound will primarily exist in the dissociated form at environmentally relevant pHs. If released to air, SDMC will exist solely in the particulate phase in the ambient atmosphere, since it is a salt and will be nonvolatile. Due to the short chemical lifetime of SDMC in air, it is not expected to accumulate in air or transported in the gaseous phase over long distances. Furthermore, based on the estimated Henry’s law constant at 25°C ＝ 6.972 1015 atmm3 mol-1at 20 °C for it and Log Pow equal to 2.41, air will not be an environmental compartment of concern and sodium N,N-dimethyldithiocarbamate can be classified as a nonadsorbed substance. Partition Behavior in Water, Sediment, and Soil The Koc of SDMC is estimated as 2.2, suggesting that SDMC is expected to have very high mobility in soil and is not adsorbed to suspended solids or sediment. Environmental Persistency Particulate-phase SDMC will be removed from the atmosphere by wet and dry depositions. Photolysis in aqueous solution and soil was found to be an important degradation process for SDMC. Depending on the geographical latitude (30–50 N) and the climatic season, the calculated environmental half-lives of SDMC range from 0.3 to 2.26 days. Hydrolysis of SDMC occurs at neutral and acidic pHs. The hydrolysis half-life of 18 min, 25.9, and 433.3 h was reported for SDMC at pH 5, 7, and 9, respectively. The products of degradation are less toxic than the product itself. 14C-SDMC is rapidly photodegraded in buffered solution at pH 9 with a calculated experimental halflife of 0.79 days, corresponding to 19 h. Direct photolysis in surface water and soil is an important degradation process for SDMC.

Purification Methods

Crystallise it from a small volume of H2O, or dissolve it in the minimum volume of H2O and add cold Me2CO, collect it and dry it in air. The solubility in Me2CO is 50g/400mL. The dihydrate loses H2O on heating at 115o to give the hemi-hydrate which decomposes on further heating [Kulka Can J Chem 34 1096 1956]. [Beilstein 4 IV 233.]

Toxicity evaluation

sodium dimethyldithiocarbamate is toxic to aquatic life and can combine to form, or break down to, a number of other toxic chemicals, including thiram (an EPA registered fungicide) and other thiurams, other dithiocarbamates, carbon disulfide, and dimethylamine. The distal peripheral and peripheral neuropathies induced by DCs are postulated to arise via a common mechanism of toxicity, that is, the formation of carbon disulfide. Chronic exposure increases brain neurotransmitters and stimulates sex hormone cycle, especially in women.

Incompatibilities

Slowly decomposes in water, forming carbon disulfide, oxides of sulfur and nitrogen, hydrogen sulfide, ammonia, and amines, including methylamine; this decomposition is accelerated in the presence of acids. Flammable gases are generated by the combination with aldehydes, nitrides, and hydrides. Incompatible with acids, peroxides, and acid halides. Thiocarbamate esters are combustible. They react violently with powerful oxidizers such as calcium hypochlorite. Poisonous gases are generated by the thermal decomposition of thiocarbamate compounds, including carbon disulfide, oxides of sulfur, oxides of nitrogen, hydrogen sulfide, ammonia, and methylamine. Thio and dithiocarbamates slowly decompose in aqueous solution to form carbon disulfide and methylamine or other amines. Such decompositions are accelerated by acids. Flammable gases are generated by the combination of thiocarbamates with aldehydes, nitrides, and hydrides. Thiocarbamates are incompatible with carboxylic acid acids, peroxides, and acid halides.

Waste Disposal

Dispose of contents and container to an approved waste disposal plant. All federal, state, and local environmental regulations must be observed.

Application

The methyl ester of dimethyldithiocarbamic acid is produced by the reaction of sodium dimethyldithiocarbamate with dimethyl sulfate in aqueous medium in the presence of a small amount of emulsifier at 40° to 50° C.Dimethyldithiocarbamic Acid Sodium Salt was used in studies to develop removal of heavy metals from water by sulfide precipitation.Sodium N,N-dimethylthithiocarbamate is use as a disinfectant, corrosion inhibitor, coagulant, vulcanizing agent, chelating agent, and fungicide may result in its release to the environment through various waste streams(SRC). It is also used as an antimicrobial agent in paints.

General Description

Crystals or liquid. Becomes anhydrous at 266°F.