Carbon disulfide

Description

For many years, carbon disulfide was manufactured by the reaction of charcoal with sulfur vapor at temperatures of 750– 1000
C, but by the mid-twentieth century, especially in the United States, the process was superseded by the reaction of natural gas (principally methane) with sulfur.

Description

Carbon disulfide (CS2) was once a common laboratory and industrial solvent, but it is used less widely now because of its toxicity and flammability. It was once manufactured by the reaction of sulfur with carbon sources, such as charcoal or coke, at high temperatures; but it is now made by the “combustion” of natural gas in sulfur. Its major industrial uses are in the manufacture of rayon, carbon tetrachloride, and agricultural fumigants.

Chemical properties

Carbon disulfide (carbon bisulfide; CS2; CASRN 75-15-0), in its pure form is a colorless liquid that evaporates readily at room temperature, with a sweet aromatic odor similar to that of chloroform. In its impure commercial and reagent form, however, carbon disulfide is a yellowish liquid with a foulsmelling odor. It can be detected by odor at about 1 ppm but the sense of smell fatigues rapidly and, therefore, odor does not serve as a good warning property. It has a vapor pressure of 297mmHg and solubility in water by weight of 0.3% at 20 °C (68 °F). Once carbon disulfide is in the air it will break down into simpler substances within a few days after release (OEHHA, 2001).

Physical properties

Clear, colorless to pale yellow liquid; ethereal odor when pure. Technical grades have strong, foul, rotten, radish-like odor. Leonardos et al. (1969) reported an odor threshold in air of 210 ppb_v.

The Uses of Carbon disulfide

Carbon disulfide is used as a raw material in the production of such things as rayon, cellophane, semiconductors, and carbon tetrachloride, and to make some pesticides. It is used as an industrial solvent and chemical intermediate to dissolve rubber to produce tires (ATSDR, 1996), as well as in grain fumigation, analytical chemistry research, degreasing, dry cleaning, and oil extraction (Finkel et al., 1983). Natural sources of carbon disulfide include the open ocean, coastal areas of high biological activity, microbial reduction of sulfates in soil, marshlands, and some higher plants where the source of carbon disulfide is the tree roots (Carroll, 1985; Khalil and Rasmussen, 1984).
Previously, carbon disulfide was used as a pesticide, where it was typically mixed with carbon tetrachloride in a 20/80 mixture, respectively. This mixture was used to exterminate insects and rodents from entire boxcars of wheat, corn, rye, and other grains (Peters et al., 1988). Grain fumigators can be acutely intoxicated and may be chronically exposed to carbon disulfide. Therefore, in the late 1980s, all pesticides containing carbon disulfide as an active ingredient were cancelled by the United States Environmental Protection Agency (U.S. EPA) (U.S. EPA, 1999).

The Uses of Carbon disulfide

In the manufacture of rayon, carbon tetrachloride, xanthogenates, soil disinfectants, electronic vacuum tubes. Solvent for phosphorus, sulfur, selenium, bromine, iodine, fats, resins, rubbers.

The Uses of Carbon disulfide

Carbon disulfide is used in the manufacture of regenerated cellulose rayon, cellophane, soil disinfectants, and electronicvacuum tubes. Other major uses are in theproduction of carbon tetrachloride, xanthates,thiocyanates, plywood adhesives, and rubberaccessories. It is also used as a solvent and asan eluant for organics adsorbed on charcoalin air analysis.

Preparation

Carbon disulfide is manufactured by heating sulfur vapor with charcoal, and condensing vapors of the compound formed. Alternatively, it may be obtained by heating sulfur with natural gas or petroleum fractions. Instead of sulfur, H2S may be used. The reaction occurs at very high temperatures. The product obtained in these reactions may contain sulfur impurities. Carbon disulfide is purified by distillation.

Definition

ChEBI: Carbon disulfide is an organosulfur compound and a one-carbon compound.

General Description

Pure carbon disulphide is a colourless liquid with a pleasant odour similar to that of chloroform, while the impure carbon disulphide is a yellowish liquid with an unpleasant odour, like that of rotting radishes. Exposure to carbon disulphide occurs in industrial workplaces. Industries associated with coal gasification plants release more of carbon disulphide, carbonyl sulphide, and hydrogen sulphide. Carbon disulphide is used in large quantities as an industrial chemical for the production of viscose rayon fibres. In fact, the major source of environmental pollution both indoor and outdoor by carbon disulphide is caused by emission released into the air from viscose plants.

Air & Water Reactions

Highly flammable. Insoluble in water.

Reactivity Profile

Carbon disulphide has an extremely low autoignition temperature (125°C). May ignite or even explode when heated. The vapor or liquid has been known to ignite on contact with steam pipes, particularly if rusted [Anon., J. Roy. Inst. Chem., 1956, 80, p.664]. Explosion hazard when exposed to flame, heat, sparks or friction. Mixtures with lithium, sodium, potassium or dinitrogen tetraoxide may detonate when shocked. Potentially explosive reaction with nitrogen oxide, chlorine, permanganic acid(strong oxidizing agents). Vapor ignites in contact with aluminum powder or fluorine. Reacts violently with azides, ethylamine ethylenediamine, ethylene imine. Emits highly toxic fumes of oxides of sulfur when heated to decomposition [Bretherick, 5th ed., 1995, p. 663]. Sodium amide forms toxic and flammable H2S gas with CS2. (714)

Hazard

A poison. Toxic by skin absorption. Highly flammable, dangerous fire and explosion risk, can be ignited by friction. Explosive limits in air 1–50%. Questionable carcinogen. Peripheral ner- vous system impairment.

Health Hazard

Although carbon disulfide exhibits lowtoxicity in most experimental animals, itstoxicity is relatively greater in humans. Theprimary route of exposure is inhalation ofvapors. It may also enter the body throughskin absorption. The toxic effect from single exposure is narcosis. Repeated exposure causes headache, dizziness, fatigue, nervousness, insomnia, psychosis, irritation, tremors,loss of appetite, indigestion, and gastric disturbances. The symptoms above may be manifested in humans after a few months of 4-hour daily exposure to 150 ppm. A concentration below 30 ppm does not produce anynotable toxic effects. A 15-minute exposureto 5000 ppm of carbon disulfide in air can befatal to humans. Ingestion of 5–10 mL of theliquid may be fatal. The oral LD50 value inrats is in the range 3000 mg/kg.
Chapman et al. (1991) reported finger tremor in humans similar to idiopathic Parkinson’s disease resulting from chronic exposureto carbon disulfide-based pesticides. Similarneurotoxic effects of the pesticide disulfiram have been earlier attributed to its metabolite,CS2 (Rainey Jr. 1977). Sills et al. (2005) haveconducted neurotoxicity inhalation studies ofCS2 onthetargetorgansspinalcordofthecen-tral nervous system and the distal portions oflong myelinated axons of peripheral nervoussystem in F344 rats. The authors observedthat CS2 produced intra- and intermolecularprotein cross-linking in vivo. Such covalentcross-linking in neurofilament proteins priorto the onset of lesions contributed to the neu-rofilamentous axonal swellings.
Chou et al. (2005) have investigated CS2-induced skin toxicity in mice and alterationsin epidermal permeability leading to physiological and pathological changes from topicalexposure to CS2. The authors have postulated two mechanistic pathways to accountfor CS2-induced epidermal alterations, oneinvolving intercellular lipid depletion and theother with keratinocyte damage.

Fire Hazard

Ignition temperature dangerously low: 212F. Vapors may be ignited by contact with ordinary light bulb, when heated to decomposition, Carbon disulphide emits highly toxic fumes of oxides of sulfur. When heated to decomposition, emits highly toxic fumes of sulfur oxides and can react vigorously with oxidizing materials. Avoid air, rust, halogens, metal azides, metals, oxidants; when exposed to heat or flame reacts violently with aluminum, chlorine, azides, hypochlorite, ethylamine diamine, ethylene imine, fluorine, metallic azides of lithium, potassium, cesium, rubidium and sodium, nitrogen oxides, potassium, zinc and (sulfuric acid plus permanganate). Decomposes on standing for a long time.

Flammability and Explosibility

Carbon disulfide is extremely flammable and is a dangerous fire hazard (NFPA rating = 3). It is has a high vapor pressure and extremely low autoignition temperature. Its vapor is heavier than air and can travel a considerable distance to a source of ignition and flash back. The vapor forms explosive mixtures in air at concentrations of 1.3 to 50%. Carbon disulfide can be ignited by hot surfaces such as steam baths that would ordinarily not constitute an ignition source for other flammable vapors. Rust (iron oxide) may increase the likelihood of ignition by hot surfaces. Carbon disulfide fires should be extinguished with CO2 or dry chemical extinguishers.

Safety Profile

A human poison by unspecified route. Mildly toxic to humans by inhalation. An experimental poison by intraperitoneal route. Human reproductive effects on spermatogenesis by inhalation. Experimental teratogenic and reproductive effects. Human mutation data reported. The main toxic effect is on the central nervous system, acting as a narcotic and anesthetic in acute poisoning with death following from respiratory failure. In chronic poisoning, the effect on the nervous system is one of central and peripheral damage, which may be permanent if the damage has been severe. Flammable liquid. A dangerous fire hazard when exposed to heat, flame, sparks, friction, or oxidning materials. Severe explosion hazard when exposed to heat or flame. Ignition and potentially explosive reaction when heated in contact with rust or iron. Mixtures with sodium or potassiumsodum alloys are powerful, shock-sensitive explosives. Explodes on contact with permanganic acid. Potentially explosive reaction with nitrogen oxide, chlorine (catalyzed by iron). Mixtures with dinitrogen tetraoxide are heat-, spark-, and shocksensitive explosives. Reacts with metal azides to produce shockand heat-sensitive, explosive metal azidodtthioformates. Aluminum powder ignites in CS2 vapor. The vapor ignites on contact with fluorine. Reacts violently with azides, CsN3, Cl0, ethylamine diamine, ethylene imine, Pb(N3)2, LiN3, (H2so4 + permanganates), KN3, RbN3, NaN3, phenylcoppertriphenylphosphine complexes. Incompatible with air, metals, oxidants. To fight fire, use water, CO2, dry chemical, fog, mist. When heated to decomposition it emits highly toxic fumes of SO,.

Potential Exposure

Carbon disulfide is used in the manufacture of viscose rayon; ammonium salts; carbon tetrachloride; carbanilide, xantho genates; flotation agents; soil disinfectants; dyes; electronic vacuum tubes; optical glass; paints, enamels, paint removers; varnishes; varnish removers; tallow, textiles, explosives; rocket fuel; putty; preservatives, and rubber cement; as a solvent for phosphorus, sulfur, selenium, bromine, iodine; alkali cellulose; fats, waxes, lacquers, camphor, resins, and cold vulcanized rubber. It is also used in degreasing; chemical analysis; electroplating; grain fumigation; oil extraction; and drycleaning. It is widely used as a pesticide intermediate.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.

Source

Identified among 139 volatile compounds identified in cantaloupe (Cucumis melo var.reticulates cv. Sol Real) using an automated rapid headspace solid phase microextraction method (Beaulieu and Grimm, 2001).

Environmental Fate

Chemical/Physical. Carbon disulfide hydrolyzes in alkaline solutions to carbon dioxide and hydrogen disulfide (Peyton et al., 1976).
In an aqueous alkaline solution containing hydrogen peroxide, dithiopercarbonate, sulfide, elemental sulfur and polysulfides may be expected to form (Elliott, 1990). In an aqueous alkaline solution (pH ≥8), carbon disulfide reacted with hydrogen peroxide forming sulfate and carbonate ions. However, when the pH is lowered to 7–7.4, colloidal sulfur is formed (Adewuyi and Carmichael, 1987).
An aqueous solution containing carbon disulfide reacts with sodium hypochlorite forming carbon dioxide, sulfuric acid and sodium chloride (Patnaik, 1992). Forms a hemihydrate which decomposes at –3°C (Keith and Walters, 1992).Agricultural fumigant Burns with a blue flame releasing carbon dioxide and sulfur dioxide (Windholz et al., 1983). Emits very toxic sulfur oxides when heated to decomposition (Lewis, 1990). Carbon disulfide oxidizes in the troposphere producing carbonyl sulfide. The atmospheric half-lives for carbon disulfide and carbonyl sulfide were estimated to be approximately 2 years and 13 days, respectively (Khalil and Rasmussen, 1984).

storage

carbon disulfide should be used only in areas free of ignition sources (including hot plates, incandescent light bulbs, and steam baths), and this substance should be stored in tightly sealed metal containers in areas separate from oxidizers.

Shipping

UN1131 Carbon disulfide, Hazard Class: 3; Labels: 3-Flammable liquid, 6.1-Poisonous materials.

Purification Methods

Shake it for 3hours with three portions of KMnO4 solution (5g/L), twice for 6hours with mercury (to remove sulfide impurities) until no further darkening of the interface occurs, and finally with a solution of HgSO4 (2.5g/L) or cold, saturated HgCl2. Dry it with CaCl2, MgSO4, or CaH2 (with further drying by refluxing over P2O5), followed by fractional distillation in diffuse light. Alkali metals cannot be used as drying agents. It has also been purified by standing with bromine (0.5mL/L) for 3-4hours, shaking rapidly with KOH solution, then copper turnings (to remove unreacted bromine), and drying with CaCl2. CS2 is highly TOXIC and highly FLAMMABLE. Work in a good fumehood. Small quantities of CS2 have been purified (including removal of hydrocarbons) by mechanical agitation of a 45-50g sample with a solution of 130g of sodium sulfide in 150mL of H2O for 24hours at 35-40o. The aqueous sodium thiocarbonate solution is separated from unreacted CS2, then precipitated with 140g of copper sulfate in 350g of water, with cooling. After filtering off the copper thiocarbonate, it is decomposed by passing steam into it. The distillate is separated from H2O and distilled from P2O5. [Ruff & Golla Z Anorg Chem 138 17 1924, Beilstein 3 IV 395.]

Toxicity evaluation

Carbon disulfide is a clear, colorless or faintly yellow, mobile liquid at room temperature, and has an ‘ether-like’ odor. It is highly flammable and volatile. It has a solubility of 2160 mg l^-1 in water at 25°C, and is very slightly soluble in water, as well as in alcohol, benzene, ether, chloroform, carbon tetrachloride, and oils. If released to air, an estimated vapor pressure of 359 mmHg at 25°C indicates that carbon disulfide will exist solely as a vapor in the ambient atmosphere and may potentially volatilize from dry soil surfaces given its vapor pressure. Based on the estimated Henry’s law constant of 1.44×10² atm-m³ mol1 at 24°C for carbon disulfide, volatilization is expected to occur from moist soil surfaces and rapidly from water surfaces. Other physical properties include an octanol/water partition coefficient as log Pow of 1.84, a boiling point of 46°C, and a melting point of 111°C.

Incompatibilities

Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Also incompatible with chemically active metals (such as sodium, potassium, zinc), azides, organic amines, halogens. May explosively decompose on shock, friction, or concussion. May explode on heating. The substance may spontaneously ignite on contact with air and on contact with hot surfaces, producing toxic fumes of sulfur dioxide. Reacts violently with oxidants to produce oxides of sulfur and carbon monoxide, and causing fire and explosion hazard. Attacks some forms of plastic, rubber, and coating.

Waste Disposal

This compound is a very flammable liquid which evaporates rapidly. It burns with a Blue flame to carbon dioxide (harmless) and sulfur dioxide. Sulfur dioxide has a strong suffocating odor; 1000 ppm in air is lethal to rats. The pure liquid presents an acute fire and explosion hazard. The following disposal procedure is suggested: All equipment or contact surfaces should be grounded to avoid ignition by static charges. Absorb on vermiculite, sand, or ashes and cover with water. Transfer underwater in buckets to an open area. Ignite from a distance with an excelsior trail. If quantity is large, Carbon disulfide may be recovered by distillation and repackaged for use.

Precautions

During handling of carbon disulfi de, occupational workers require proper clothing, eye protection, and respiratory protection. Workers should use the chemical under trained management. On contact with the eyes, immediately fl ush with large amounts of water. On skin contact, the worker should quickly remove contaminated clothing and immediately call for medical attention