Metham sodium

129.18

128.96800

205-293-0

3CD7UKN224

3267|2588

DTXSID2029167

White crystals|White crystalline solid

2930909090

69.42000

1.07910

Liquid

Decomposes without melting

120.3ºC at 760mmHg

26.6ºC

H2O: 72.2 g/100 mL at 20 ºC

APPROX -18°C

Non-volatile

Oral-Rat  LD50: 450 mg/kg; Oral-Mouse LD50: 50 mg/kg

Combustion produces toxic sulfur oxide gas

Colorless crystals. /Dihydrate/|IN DIL AQ SOLN, AT PH 9.5, VAPAM DECOMPOSES TO METHYL ISOTHIOCYANATE AND SULFUR; UNDER ACID CONDITIONS, CARBON DISULFIDE, HYDROGEN SULFIDE, N,N'-DIMETHYLTHIURAM DISULFIDE, METHYLAMINE, METHYL ISOTHIOCYANATE ARE FORMED.|A soil fungicide, nematocide, & herbicide reputed to act by decomposition in moist soil to methyl isothiocyanate. If true, this may be a unique property of metham, as opposed to many closely related chemicals used for much of the same purposes, eg, ferbam, nabam, ziram, zineb, & maneb.

Slow reaction upon dilution produces toxic gases hydrogen sulfide and methylisothiocyanate. This reaction is accelerated by the addition of acid.

Thiocarbamate Esters and Salts/Dithiocarbamate Esters and Salts

Water-Reactive

METAM SODIUM is a dithiocarbamate. Flammable gases are generated by the combination of thiocarbamates and dithiocarbamates with aldehydes, nitrides, and hydrides. Thiocarbamates and dithiocarbamates are incompatible with acids, peroxides, and acid halides. It will decompose upon dilution to carbon disulfide, monomethylamine, methylisothiocyanate, and hydrogen sulfide. The decomposition products are flammable and toxic. The acute symptoms of exposure to metam sodium are excessive salivation, sweating, fatigue, weakness, nausea, headache, dizziness, eye and respiratory tract irritation, and skin irritation in the form of rashes. The spillage of a rail car tanker of metam sodium into the Sacramento River caused a major fish kill (over a million trout) along several miles of that river.

Non flammable. /Metham Sodium Dihydrate/

THE AQUEOUS SOLUTION IS CORROSIVE TO BRASS, COPPER AND ZINC|Aluminum, very rapid corrosion; mild steel, 0.7 mg/day/sq m; stainless steel, <0.2 mg/day/sq m

III

6.1(b)

UN 2811

22-31-34-50/53-43

26-36/37/39-45-60-61

FC2100000

C;N,N,C

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

Metam-sodium is stable in its dry, crystalline state, and in concentrated aqueous solution. Metam-sodium is very stable at a pH greater than 8.8, but at pH 7 and below it readily hydrolyzes. In soil or when diluted with water, metam-sodium is converted to methyl isothiocyanate (MITC). Other degradates of metam-sodium include carbon disulfide (CS2) and hydrogen sulfide (H2S).

P260, P261, P264, P270, P272, P273, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P330, P333+P313, P363, P391, P405, P501

H302

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.|Pesticide disposal: Pesticide wastes are toxic. Improper disposal of excess pesticide, spray mixture, or rinsate is a violation of Federal law. If these wastes cannot be disposed of by use according to label instructions, contact your State Pesticide or Environmental Control Agency, or the Hazardous Waste Representative at the nearest EPA regional office for guidance. /Vapam/|Container Disposal: Triple rinse or equivalent. Then offer for recycling or reconditioning, or puncture and dispose of in a sanitary landfill, or if allowed by state and local authorities, by burning. If burned, stay out of smoke. /Vapam/|This pesticide is toxic to fish. Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans or public waters unless in accordance with the requirements of a National Pollutant Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer systems without previously noti'ing the local sewage treatment plant authority. For guidance, contact your State Water Board or Regional Office of the Environmental Protection Agency. /Vapam/

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision (RED) for Methyldithiocarbamate Salts -Metam Sodium/Potassium and MITC 142 p. EPA 738-R-08-006 (July 2008). Available from the Database Query page at http://www.epa.gov/pesticides/reregistration/status.htm as of October 3, 2008.|USEPA Office of Pesticide Programs; RED Fact Sheet: Methyldithiocarbamate Salts - Metam Sodium/Potassium and MITC 8 pp. (July 10, 2008) Available from the Database Query page at http://www.epa.gov/pesticides/reregistration/status.htm as of October 3, 2008.|California Environmental Protection Agency/Department of Pesticide Regulation; Toxicology Data Review Summaries. Available from: http://www.cdpr.ca.gov/docs/toxsums/toxsumlist.htm on Metam-sodium as of February 20, 2008.|USEPA/OPP; Health Effects Division (7509C). Metam Sodium: Revised HED Human Health Risk Assessment For Phase 3: DP Barcode: D318051, Metam Sodium PC Code: 039003, MITC PC Code: 068103 (JUNE 20, 2005) EPA-HQ-OPP-2005-0125-003. Available from the Database Query page at http://www.regulations.gov as of February 19, 2008.|For more Special Reports (Complete) data for SODIUM METHYLDITHIOCARBAMATE (6 total), please visit the HSDB record page.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form. (ERG, 2016)

|Danger|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P260, P261, P264, P270, P272, P273, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P330, P333+P313, P363, P391, P405, and P501|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P260, P261, P264, P270, P271, P272, P273, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P333+P313, P361, P363, P391, P405, and P501|Aggregated GHS information provided by 235 companies from 5 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Aggregated GHS information provided by 38 companies from 1 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Warning|P201, P202, P260, P261, P264, P270, P271, P272, P280, P281, P301+P312, P302+P352, P304+P340, P305+P351+P338, P308+P313, P309+P311, P312, P321, P322, P330, P332+P313, P333+P313, P337+P313, P362, P363, P403+P233, P405, and P501

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2016)

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. (ERG, 2016)|Approved respirator. Chemical-resistant apron when cleaning equipment, mixing or loading. Chemical-resistant headgear for overhead exposure. Protective eyewear. handlers in enclosed cabs: Coveralls, shoes, and socks. If pungent rotten egg odor of product can be detected inside of cab, face-sealing goggles, unless full-face respirator is worn.|Personnel protection: ... Wear appropriate chemical protective gloves, boots and goggles. ... Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Thiocarbamate pesticides, liquid, toxic, flammable; Thiocarbamate pesticides, liquid, flammable, toxic; Thiocarbamate pesticides, solid, toxic/|Personnel protection: ... Wear positive pressure self-contained breathing apparatus. ... Wear appropriate chemical protective clothing. /Thiocarbamate pesticides, liquid, toxic/

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide. /Thiocarbamate pesticides, liquid, toxic, flammable; Thiocarbamate pesticides, liquid, flammable, toxic/|If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Solid streams of water may be ineffective. Use foam, dry chemical or carbon dioxide. /Thiocarbamate pesticides, liquid, toxic/|If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire (Material itself does not burn or burns with difficulty). Use water in flooding quantities as fog. Use "alcohol" foam, dry chemical or carbon dioxide. /Thiocarbamate pesticides, solid, toxic/

Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ /Thiocarbamate pesticides, liquid, toxic, flammable; Thiocarbamate pesticides, liquid, flammable, toxic; Thiocarbamate pesticides, liquid, toxic/|Environmental considerations: Water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses. /Thiocarbamate pesticides, liquid, toxic, flammable; Thiocarbamate pesticides, liquid, flammable, toxic; Thiocarbamate pesticides, liquid, toxic/|Environmental considerations: Air spill: Apply water spray or mist to knock down vapors. /Thiocarbamate pesticides, liquid, toxic, flammable; Thiocarbamate pesticides, liquid, flammable, toxic; Thiocarbamate pesticides, liquid, toxic/|Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ /Thiocarbamate pesticides, solid, toxic/|Environmental considerations: Water spill: Use natural barriers or oil spill control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses. /Thiocarbamate pesticides, solid, toxic/

To reduce the potential for metam-sodium and metam-potassium exposure to bystanders, handlers, and workers, and to address associated risks of concern, EPA is requiring a number of mitigation measures which include: (1) Buffer zones; (2) Dermal protection for handlers; (3) Respiratory protection and air monitoring for handlers; (3) Restrictions on the timing of perforation and removing of tarps; (4) Posting; (5) Good agricultural practices; (6) Fumigant management plans; (7) Emergency preparedness and response plans; (8) Notice to state lead agencies. The Agency also believes that registrant-developed training and community outreach programs, which are also implemented by the registrant, will help reduce risk. Additionally, EPA is interested in working with registrants to identify additional measures that could be implemented as part of product stewardship. These additional measures should include efforts to assist users' transition to the new label requirements. Some of the required mitigation measures only address one group of potentially exposed individuals (i.e., bystanders, handlers, or workers), while other measures will help reduce risk to more than one group. All mitigation measures are designed to work together to reduce exposures, enhance safety, and facilitate compliance and enforcement. ... EPA has determined that these measures, working together, will prevent unreasonable adverse effects on human health.|Buffer zones, of varying sizes based on application method, application rate, and application block size, and emission control measures are required /for fumigant use/. Buffer zones will be in effect from the time the fumigation begins until 48 hours following the application.|/For fumigant use/ EPA is requiring that buffer zones be posted at usual points of entry and along likely routes of approach to the buffer unless (1) a physical barrier such as a fence prevents access to the buffer, or (2) all of the area within 300 feet of the buffer is under the control of the owner/operator. The posting requirement is intended to prevent passersby from entering a buffer zone.|/Fumigant/ Handlers exposed to MITC vapors from metam sodium/potassium or MITC applications will either wear respirators or follow an air monitoring program. Additional dermal PPE is required for some handler tasks.|For more Preventive Measures (Complete) data for SODIUM METHYLDITHIOCARBAMATE (27 total), please visit the HSDB record page.

/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Health: TOXIC; may be fatal if inhaled, ingested or absorbed through skin. Inhalation or contact with some of these materials will irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution. /Dithiocarbamate pesticide, liquid, flammable, poisonous; Dithiocarbamate pesticide, liquid, flammable, toxic; Dithiocarbamate pesticide, liquid, poisonous, flammable; Dithiocarbamate pesticide, liquid, toxic, flammable/|/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion and poison hazard indoors, outdoors or in sewers. Those substances designated with a "P" may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water. /Dithiocarbamate pesticide, liquid, flammable, poisonous; Dithiocarbamate pesticide, liquid, flammable, toxic; Dithiocarbamate pesticide, liquid, poisonous, flammable; Dithiocarbamate pesticide, liquid, toxic, flammable/|/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Public Safety: CALL Emergency Response Telephone Number ... . As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering. /Dithiocarbamate pesticide, liquid, flammable, poisonous; Dithiocarbamate pesticide, liquid, flammable, toxic; Dithiocarbamate pesticide, liquid, poisonous, flammable; Dithiocarbamate pesticide, liquid, toxic, flammable/|/GUIDE 131: FLAMMABLE LIQUIDS-TOXIC/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. /Dithiocarbamate pesticide, liquid, flammable, poisonous; Dithiocarbamate pesticide, liquid, flammable, toxic; Dithiocarbamate pesticide, liquid, poisonous, flammable; Dithiocarbamate pesticide, liquid, toxic, flammable/|For more DOT Emergency Guidelines (Complete) data for SODIUM METHYLDITHIOCARBAMATE (16 total), please visit the HSDB record page.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Irritating to skin, mucous membranes.|Sodium N-methyldithiocarbamate (vapam) ... is reported to be irritating to the eyes ...|It irritates eyes, nose, and throat. /Vapam/

Sodium methyldithiocarbamate (approx 72,000 liters) was accidently released into the Upper Sacramento River on July 14, 1991 due to a railroad car derailment(1).

highly toxic

The drug acts by interfering with alcohol metabolism so that the ingestion of alcohol is followed by distressing & occasionally dangerous symptoms. ... The disulfiram-alcohol reaction ... is not a simple intensification of alcoholic intoxication, although this may play a role. ... The acute drug-alcohol reaction ... is usually considered unpleasant, at times alarmingly so. It consists of flushing, headache, vasodilation, tachycardia, hypotension (after a transient rise in systolic pressure), nausea, restlessness, confusion & many other signs & symptoms. ... The disulfiram-alcohol reaction appears at the same time as excessive concentrations of acetaldehyde in the blood. The enzyme alcohol dehydrogenase generates acetaldehyde from ethanol. Acetaldehyde accumulates presumably because disulfiram inhibits aldehyde dehydrogenase, the enzyme which normally oxidizes this intermediary product of alcohol metabolism to "active" acetate. ... Disulfiram is a potent inhibitor of dopamine beta-oxidase. This enzyme requires copper, which disulfiram apparently removes by chelation. Dopamine beta-oxidase is an essential enzyme in the norepinephrine biosynthetic pathway. ... Disulfiram /exposure/ leads to the depletion of norepinephrine at adrenergic nerve terminals. ... With the sympathomimetic effects of acetaldehyde blocked by disulfiram depletion of the adrenergic transmitter, the direct vasodilator effect of acetaldehyde is unmasked. The latter is presumably responsible for the fall in blood pressure in the disulfiram-alcohol reaction. /Disulfiram/|The effects of dithiocarbamates on the tissue distribution and excretion of lead were examined in rats, with special emphasis on the central nervous system. /One of the compounds tested was/ sodium monomethyldithiocarbamate (metham). Male Sprague-Dawley rats received radioactively labeled lead acetate injected into a tail vein. The dithiocarbamates or thiurams were administered by gastric intubation. One dose was given 2 hr before lead, and another immediately after. The uptake of lead by the brain was increased by ... metham. /It was concluded that/ combined exposure to lead and dithiocarbamates should be avoided.

LD50 Rat (male) oral 780 mg/kg /From table/|LD50 Rat oral 1700 mg/kg|LD50 Rat (female) oral 845 mg/kg /From table/|LD50 Rat oral 820 mg/kg /Sodium methyldithiocarbamate, dihydrate/|For more Non-Human Toxicity Values (Complete) data for SODIUM METHYLDITHIOCARBAMATE (19 total), please visit the HSDB record page.

/AQUATIC SPECIES/ Lepomis macrochirus (bluegill) was exposed to metam-sodium (aq formulation containing 42.2% methylcarbamodithionic acid monosodium salt as ai corresponding to 510 g/L) in a static system for 86 /or 96/ hr. NOEC/LC0 = 0.215 mg/L (nominal concentration) and LC50 = 0.175 to 0.82 mg/L/86 or 96 hr (analytically detected concentration). Symptoms: abnormal swimming behavior and apathy. /Metam-sodium aq formulation containing 42.2% methylcarbamodithionic acid monosodium salt as ai corresponding to 510 g/L/|/AQUATIC SPECIES/ /Oncorhynchus mykiss (Rainbow trout)/ was exposed to metam-sodium (aqueous formulation containing 42.2% methylcarbamodithionic acid monosodium salt as ai corresponding to 510 g/L) in a static system for 96/ hr. NOEC = 0.464 mg/L (nominal concentration); LC0 = 21.5 mg/L (nominal concentration); and LC50 = 35 mg/L/96 hr (analytically detected concentration). Symptoms: discoloration, gasping, lying on the bottom, /CNS depressed/-like state, tumbling. /Metam-sodium aq formulation containing 42.2% methylcarbamodithionic acid monosodium salt as ai corresponding to 510 g/L/

Sodium methyldithiocarbamate's production may result in its release to the environment through various waste streams; its use as a soil fumigant(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: /IT IS/ NON-PERSISTENT IN SOIL AND DISAPPEARS, UNDER MOIST CONDITIONS, WITHIN 2 WK.|TERRESTRIAL FATE: METHAM ... IS DEGRADED IN SOIL TO METHYLISOTHIOCYANATE AND HYDROGEN SULFIDE. ONE ALSO EXPECTS THAT SIMPLE HYDROLYSIS SHOULD FORM METHYL AMINE AND CARBON DISULFIDE.|TERRESTRIAL FATE: Methan is weakly adsorbed to soil ... subject to photolysis ... typical field half-life is 7 days ... not volatile /Metham/|TERRESTRIAL FATE: Sodium methyldithiocarbamate hydrolyzes rapidly(1) and therefore is unlikely to adsorb to soil(SRC). Volatilization of sodium methyldithiocarbamate from moist soil or dry soil surfaces is not expected to be an important fate process(SRC) as the compound is non-volatile(2). Sodium methyldithiocarbamate is extremely hygroscopic and unstable as the dry salt(3), exhibiting a half-life of approximately 0.06 days(2). It breaks down in moist soil to methyl isothiocyanate, the acid exhibiting a half-life range of 0.23 minutes to 4 days(3). Sodium methyldithiocarbamate was degraded 73-96% to methyl isothiocyanate within 0.1 to 4 days using acclimated and unacclimated soil inoculums(4); however its rapid transformation via abiotic processes leaves the importance of biodegradation as inconclusive(SRC).|For more Environmental Fate (Complete) data for SODIUM METHYLDITHIOCARBAMATE (6 total), please visit the HSDB record page.

Sodium methyldithiocarbamate is extremely hygroscopic and unstable(1). In soil, sodium methyldithiocarbamate rapidly decomposes to methyl isothiocyanate, DT50 23 min to 4 days(2). A half-life in the field of 7 days has been reported(3). In dilute aqueous solutions at pH 9.5, sodium methyldithiocarbamate decomposes to methyl isothiocyanate and elemental sulfur were also formed(4). In acidic solutions, sodium methyldithiocarbamate breaks down to carbon disulfide, hydrogen sulfide, methylamine, methyl isothiocyanate, and N,N-dimethyl thiuram disulfide(4). Sodium methyldithiocarbamate was listed as undergoing hydrolytic nucleophilic transformations and chemical oxidation in soil(5). At a concentration of 1,000 ppm in water, sodium methyldithiocarbamate required more than 3 weeks for complete decomposition at room temperature; adding 20% soil to the mixture sped up the rate of decomposition considerably(6).|Sodium methyldithiocarbamate is stable in concentrated aqueous solution, but is unstable when diluted. Decomposition is promoted by acids and heavy-metal salts. Hydrolysis half-lives were reported as follows (25 °C): 23.8 hours (pH 5), 180 hours (pH 7), 45.6 hours (pH 9). Solutions exposed to sunlight exhibited a half-life of 1.6 hours at pH 7, 25 °C(1). In the dark, the compound exhibited a half-life of 35 hrs at 25 °C, based on a rate constant of 3.3X10-4.min(2). Despite weak absorption of near-UV light, sodium methyldithiocarbamate photodegraded rapidly with a near-UV quantum yield of 0.36; photoproducts included methylthiourea and 1,3-dimethylthiourea(2).|The conversion rate of metham-sodium to methyl isothiocyanate (MIT) in soil was dependent on soil type & temp & the half life varied up to several weeks. In soil the conversion was apparently complete after only a few hr. Degradation of vapam & methylisothiocyanate in soils followed first order kinetics. Breakdown of vapam & MIT followed first order kinetics; & the breakdown of vapam to MIT was generally less than 30 min.

Sodium methyldithiocarbamate hydrolyzes rapidly to form methyl isothiocyanate(1) and therefore is unlikely to bioconcentrate in aquatic organisms(SRC).

Sodium methyldithiocarbamate hydrolyzes rapidly to form methyl isothiocyanate(1) and therefore is unlikely to adsorb or leach(SRC). In soil, this transformation occurs at an extent >90% (following first-order kinetics), corresponding to a half-life of about 0.06 days at 25 °C(2). However, a coefficient of adsorption on soil organic matter (Kom) of 228 L/kg has been reported(2).

When applied to moist soil surface without soil incorporation, metham itself is not volatile; but its main breakdown product, methyl isothiocyanate, is rapidly lost by volatility. /Metham/|Sodium methyldithiocarbamate is essentially nonvolatile from water surfaces and dry soil surfaces(1). The major transformation product of sodium methyldithiocarbamate is methyl isothiocyanate, which volatilizes rapidly(2,3). In soil, this transformation occurs at an extent >90% (following first-order kinetics), corresponding to a half-life of about 0.06 days(3).

GROUNDWATER: Sodium methyldithiocarbamate was not detected in 33 wells sampled in 2 counties from California from July 1, 1994 to June 30, 1995(1). Sodium methyldithiocarbamate was used on 2 of 91 farms in a heavily agricultural area in Ontario, Canada, 1984 but was not detected in any groundwater samples tested (detection limit 0.1 ug/L)(2).|SURFACE WATER: Sodium methyldithiocarbamate was not detected in the Sacramento River in southern California following a July 1991 spill of 75,700 liters of the compound; only its more toxic and volatile product, methyl isothiocyanate, was detected downstream at approximately 50% of the total sodium methyldithiocarbamate amount released(1).

Occupational exposure to sodium methyldithiocarbamate may occur through inhalation and dermal contact with this compound at workplaces where sodium methyldithiocarbamate is produced or used. The general population exposure should be low or non-existent since sodium methyldithiocarbamate has a relatively short environmental lifetime; however exposure to its degradation product, methyl isothiocyanate, is likely given the latter's persistence in the environment. (SRC)

Agents that kill parasitic worms. They are used therapeutically in the treatment of HELMINTHIASIS in man and animal. (See all compounds classified as Anthelmintics.)|Chemicals used to destroy pests of any sort. The concept includes fungicides (FUNGICIDES, INDUSTRIAL); INSECTICIDES; RODENTICIDES; etc. (See all compounds classified as Pesticides.)|Substances used in the treatment or control of nematode infestations. They are used also in veterinary practice. (See all compounds classified as Antinematodal Agents.)

Pharmacokinetic and metabolism studies in rats for ... metam sodium ... /were/ tested at two /oral/ dose levels. It was ... excreted mainly in urine with urinary recoveries over 168 hr of ... 37 to 58% ... Excretion via the feces was low --usually ranging from 1.5% to 3.3%. Three different cmpd (MITC, CO2, COS/CS2 ) were found to be excreted via the lungs. Total excretion of the 3 products of the lungs over a 73 hr collection period were about 35% and 50% ... at low and high doses, respectively. There were no differences between males and females in amt excreted via the three excretion routes. Tissue retention at 168 hr was about 2% ... at both dose levels. Total recoveries, incl the % of the doses excreted and that remaining in the tissues combined after 168 hr, ranged from 92.6% to 106%, indicating virtually complete absorption from the GI tract. By the first 24 hr, 85% or more ... at both dose levels had been excreted. /Metam sodium was/ rapidly absorbed from the GI tract with plasma t-max between 0.25 and 1.0 hr. However, plasma half-lives after 24 hr were long, ranging from around 60 to 74 hr ... Tissue and plasma levels at all time periods, and plasma AUCs were consistently higher in females than in males by a substantial amt. The tissue with the highest uptake ... was the thyroid gland. High uptake were also seen by the liver, kidneys, and lung, with the lowest level in testes, brain and eyes.|(14)-Metam sodium was applied to male rats in aq formulations at the nominal dose levels of 0.1, 1 and 10 mg/rat to an area of 11.6 sq cm on the back ... The application site was protected by a glass saddle which contained an activated charcoal filter to adsorb any volatile radioactivity which evaporated from the skin surface. Within each group, 4 animals were killed following a 1, 2, 10, and 24 hr exposure and excreta collected over the study period. For 4 additional animals in each treatment group, the treatment area was washed 10 hr after admin and excretion monitored over a total of 72 hr. Mean % absorbed dose at 10 hr was 2.5% (2.355%, 3.683%, 1.514%, respectively).|Metam sodium technical (purity not stated, conc. = 512.8 g/L ... ) and (14)C-metam sodium ( ... radiochemical purity > 99%; specific activity = 64.52 uCi/mg), buffered at pH 8 (potassium phosphate), were dermally admin to female Crl:CD(SD)BR rats (5 for pretests/2 for the definitive study) at 10 mg/rat (20 uCi/rat). A "saddle" apparatus (consisting of glass) was attached to the backs of an area clipped free of hair ... Males were excluded, as their coarse body hair might have prevented adhesion of the saddle to the skin ... Activated charcoal was suspended between 2 sinters in the saddle and covered with gauze ... At 10 hr post application, the gauzes and the top sinters were removed, the charcoal was collected and the lower sinters removed /and/ ... the treated area of skin and the inside of the saddle were /cleaned/ ... Urine (0 to 4, 4 to 10, 10 to 24, 24 to 48 and 48 to 72 hr), feces (same as urine) and expired air were collected over 72 hr. Volatiles were collected in 4 expired air traps in series: 1) trap for methyl isothiocyanate, 2) carbon dioxide, 3) carbon disulphide, 4) any volatiles which may pass through the first 3 traps (air trap collection times for traps 1, 2 & 3 = same as urine; trap 4 = 0 to 72 hr). At termination, urine, feces, cage washings, cage debris, expired air traps, charcoal adsorbant, back and gauze washings (including elastic bands and sinters) were assessed for radioactivity. Rat blood was also sampled, as was residual carcass. RESULTS: Stability of metam sodium was virtually 100% of radioactivity at 24 hr. The saddle provided a non-occluded, enclosed application site with an adsorbant suspended above it. Saddles remained firmly attached for 12 to 72 hr. No pharmacological or toxicological signs were observed in test animals that were metam sodium induced. After a single dermal application of (14)C-metam sodium to 2 animals, a mean of 85% of radioactivity was recovered within 72 hr, primarily in charcoal adsorbant wash (38%), application site washings (38%) and urine (4.1%) ... MITC (0.7%) and carbon dioxide (1.9%) were the only radioactive components detected in the expired air traps. MITC was detected at a maximum between 10 to 24 hr (after removal of saddle packing). Radioactivity in feces, carcasses, cage washings, air trap 4 washings and the trap for carbon disulphide were low or below the limit of detection throughout the study. The report concluded that metam sodium was not readily absorbed during 10 hr of exposure, since < 8.2% of the applied radioactivity was recovered in urine, feces, expired air traps, cage wash and carcass ...|The biokinetics and metabolism of metam sodium was studied in rats following oral admin of nominal doses of 10 and 100 mg/kg. After a single oral dose of (14)C-metam sodium at 10 mg/kg, means of 52 and 58% dose were excreted in the urine of male and female rats during 0 to 168 hr. A total of 38% was found in the expired air of male rats during 0 to 72 hr of which 0.45% was in trap 1 (containing 2-ethoxyethanol), 19.5% dose was in trap 2 (containing sodium hydroxide soln) and 18.3% dose in trap 3 (containing Viles reagent). In female rats a total of 33.2% was found in the expired air during 0 to 72 hr of which 1.3, 18.1 and 13.8% were found in traps 1, 2, 3. Fecal excretion accounted for 4.5 and 2.9% dose in male and female rats during 0 to 168 hr. After a single oral dose of (14)C-metam sodium at 100 mg/kg, means of 37 and 42% dose were excreted in the urine of male and female rats, respectively, during 0 to 168 hr. A mean of 50% dose was excreted in the expired air of all rats of which 24.3, 6.4 and 19.5% dose were found in traps 1, 2, 3, respectively. Fecal excretion accounted for 1.9 and 1.6% dose in male and female rats. The concn of radioactivity in the tissues of rats sacrificed 168 hr after a single oral dose of (14)C-metam sodium at both doses showed that the highest levels were in the thyroids, adrenals and tissues responsible for excretion and metabolism (liver, kidneys, lungs). After a single oral dose of 10 mg/kg (14)C-metam sodium, peak mean plasma concn of radioactivity occurred at 1 hr for males and females. Within the first 48 hr mean plasma radioactivity declined with a half-live of approx 24 hr. From 72 hr to 240 hr mean concn of plasma radioactivity declined with a half-life of 60.8 hr for males and 74.1 hr for females. After a single oral dose of 100 mg/kg (14)C-metam sodium the peak mean plasma concn of radioactivity occurred at 1 to 2 hr for males and 0.25 to 1 hr for females. Mean concn of plasma radioactivity declined with a half-life of approx 24 hr (males and females) within the first 48 hr after treatment and 62 hr for males and 64 hr for females within 72 to 240 hr after treatment. Using thin-layer chromatography 2 metabolites were detected in the urine. The major metabolite, identified as N-acetyl-S-(N-methylthiocarbamoyl)-L-cycteine, represented 16 to 25% of the dose. The second metabolite, accounting for ca 5 to 10% of the admin dose, could not be exactly characterized but there is evidence that it is a similar type of conjugate as the major metabolite.|For more Absorption, Distribution and Excretion (Complete) data for SODIUM METHYLDITHIOCARBAMATE (6 total), please visit the HSDB record page.

Diethyldithiocarbamic acid, the main metabolite of disulfiram, forms methyldithiocarbamate when incubated with 14(C)-nitrosoacetoxymethylmethylamine or 14(C)-methylnitrosourea in different media (bacteria, esterases, rat liver 9000 x g supernatant fraction and microsomes). ...|Pharmacokinetic and metabolism studies in rats for ... metam sodium ... /were/ tested at two dose levels ... Three different cmpd (MITC, CO2, COS/CS2 ) were found to be excreted via the lungs. Total excretion of the 3 products of the lungs over a 73 hr collection period were about 35% and 50% ... at low and high doses, respectively.|At higher doses levels of metam sodium, the neurotoxic effects from the in vivo production of CS2 begin to manifest. Specifically, incidence of meningocele has been noted following oral administration ... Following soil application of metam sodium, both CS2 and H2S can be formed; the relative amt depend on the pH of the soil. Following oral exposure to metam sodium, rats metabolize approximately 20 to 25% of the dose (on a molar basis) to CS2. CS2 is a neurotoxic agent known to cause a variety of effects such as neuropathology and changes in sensory conduction velocity and peroneal motor conduction velocity. Exposure to H2S at low levels in humans can result in eye injury, headaches, nausea, and insomnia.|... Neither metam sodium, MITC, nor any related thioureas or methylated ureas were detected in the extractable radioactivity or the post-extraction solids. The observed radioactivity was shown to be distributed over a variety of natural products indicating complete incorporation of metam sodium into the carbon pool ... Based upon the results of the metabolism studies, residues of metam sodium and MITC are not expected to occur in plants. MITC's volatility in the environment, phytotoxity to crops, and metabolism in plants assure that there is no reasonable expectation of finite residues to be incurred in/on any raw agricultural commodity when these products are applied according to label directions.|Metam sodium technical (purity not stated, conc. = 512.8 g/L ... ) and (14)C-metam sodium ( ... radiochemical purity > 99%; specific activity = 64.52 uCi/mg), buffered at pH 8 (potassium phosphate), were dermally admin to female Crl:CD(SD)BR rats (5 for pretests/2 for the definitive study) at 10 mg/rat (20 uCi/rat) ... MITC (0.7%) and carbon dioxide (1.9%) were the only radioactive components detected in the expired air traps. MITC was detected at a maximum between 10 to 24 hr (after removal of /residual metam sodium/ ... )

Pharmacokinetic and metabolism studies in rats for ... metam sodium ... /were/ tested at two /oral/ dose levels. ... Plasma half-lives after 24 hr were long, ranging from around 60 to 74 hr ...|The biokinetics and metabolism of metam sodium was studied in rats following oral admin of nominal doses of 10 and 100 mg/kg. ... After a single oral dose of 10 mg/kg (14)C-metam sodium, peak mean plasma concn of radioactivity occurred at 1 hr for males and females. Within the first 48 hr mean plasma radioactivity declined with a half-live of approx 24 hr. From 72 hr to 240 hr mean concn of plasma radioactivity declined with a half-life of 60.8 hr for males and 74.1 hr for females. After a single oral dose of 100 mg/kg (14)C-metam sodium the peak mean plasma concn of radioactivity occurred at 1 to 2 hr for males and 0.25 to 1 hr for females. Mean concn of plasma radioactivity declined with a half-life of approx 24 hr (males and females) within the first 48 hr after treatment and 62 hr for males and 64 hr for females within 72 to 240 hr after treatment. ...

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. (ERG, 2016)

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim calm and warm. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. (ERG, 2016)

The usual measures for gut and skin decontamination are recommended for large doses. Disulfiram-alcohol reactions usually last several hours and respond to fluids, oxygen, and analgesics. Dysrhythmias may develop, and patients with serious reactions should have cardiac monitoring. /Dithio- and thiocarbamates/|Immediate first aid: Remove patient from contact with the material. Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Dithiocarbamates and Related Compounds/|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Dithiocarbamates and Related Compounds/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious or is in severe respiratory distress. Use moderate hyperventilation (rate of 20 respirations per minute) if signs of cerebral edema are present. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Dithiocarbamates and Related Compounds/

/SIGNS AND SYMPTOMS/ May be fatal if absorbed through skin.|/SIGNS AND SYMPTOMS/ The salts /of methyldithiocarbamate (sodium, ammonium, potassium)/ are irritating ... prolonged or repeated contact may cause skin burns and systemic intoxication ... .|/SIGNS AND SYMPTOMS/ In wet soil, different substances are produced as result of hydrolytic decomposition. In contact with sweating wet skin this process occurs on the skin surface. Methyl mustard oil (methylisothiocyanate) is formed as a result. Indications of an allergic response: strong focal flare-up reaction in the previous contact areas when patch testing on the back; itching and burning on the skin when in contact with nematin-containing air of the test lab or in a repair workshop; strong incorporation of radionuclides only in nematin-eczema patients as a specific reaction in the lymphocyte transformation test; and exposure time of at least one week. Metham-sodium solution may also cause toxic dermatitis with typical circinate bullae as in mustard gas. A 0.5% nematin solution (0.15% metham-sodium) causes such toxic bullous reactions.|/SIGNS AND SYMPTOMS/ Prolonged or frequently repeated skin contact may cause allergic reactions in some individuals. /Vapam/|For more Human Toxicity Excerpts (Complete) data for SODIUM METHYLDITHIOCARBAMATE (6 total), please visit the HSDB record page.

carbathione

Approximately 51-55 million pounds of metam-sodium and 1-2 million pounds of metam-potassium used in the U.S. in 2002.

Soluble concentrates, aqueous solutions.|... Since /pure metham/ is unstable, the commercial formulation (Vapam) is always kept as a concentrated 32.7% solution in water.|Trade Names ... Metam 426, Polefume, Turfcure, Vapam, Vapam HL, Busan 1236, Nemasol, Metam CLR, Sectagon 42, Sistan, Meter, Soldier|Basamid liquid (aq formulation containing 45% methylcarbamodithionic acid monosodium salt as ai); Metam-Fluid (aq formulation containing 42.2% methylcarbamodithionic acid monosodium salt as ai); VAPAM technical (technical formulation containing 32.9% methylcarbamodithionic acid monosodium salt as ai)|For more Formulations/Preparations (Complete) data for SODIUM METHYLDITHIOCARBAMATE (37 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies Metam-sodium (technical grade) as Class II: moderately hazardous; Main Use: fungicide-applied to soil: not used with herbicides or plant growth regulators.|The /USEPA/ has determined that certain uses of (1) metam sodium (including use as a pre-plant soil fumigant in certain crops, specified /in the R.E.D./, and as a root control agent in sewers and drains, and as an antimicrobial agent to treat wood poles and timbers and sewage sludge and animal waste); (2) metam-potassium (including as a pre-plant soil fumigant in certain crops, specified later in this document, and as an antimicrobial agent for treatment of pulp and paper, tanning drum leather applications, recirculating cooling water systems; and industrial water purification systems); and (3) MITC (as an antimicrobial agent to treat wood poles and pilings) are eligible for reregistration, provided the risk mitigation measures outlined in /the R.E.D./ are adopted, label amendments are made to reflect these measures ... , and data are developed to assess intermediate- and long-term risk to bystanders.|Metham-sodium was introduced by Stauffer Chemical Company & later by EI du Pont de Nemours & Company, Inc, & ICI Plant Protection Division (neither of whom now market it). US patents 2,766,554; 2,791,605; GBP /British patent/ 789,690 all Stauffer Chemical Company as code number N-869 (Stauffer); trade marks Vapam (Stauffer), VPM (formerly du Pont), Sistan (ICI).|... /Metham sodium gives/ a complete kill of root knot nematodes in sandy soil at 5 ppm. It is an effective non-selective herbicide at rates of ... 200 lb/acre. ... it is particularly effective in cracks & under walks where the methyl isothiocyanate is confined.|For more General Manufacturing Information (Complete) data for SODIUM METHYLDITHIOCARBAMATE (11 total), please visit the HSDB record page.

Product analysis is by hydrolysis to liberate carbon disulfide, which is reacted & measured by titration with iodine. Residues in crops & soils may be determined by analyzing them for methyl isothiocyanate by gas liquid chromatography.|By means of absorption of methyl isothiocyanate, a decomp product of metham-sodium, in a solid support, desorption with solvent & subsequent gas chromatographic analysis, the amt of contaminant in workroom air can be determined. The sensitivity level attainable by this gas chromatographic method is 0.02 mg of methyl isothiocyanate standard in carbon disulfide solution.

SOIL FUNGICIDES