1,1-Dichloroethane

Description

Chlorinated aliphatics as a class are known to cause central nervous system (CNS) depression and respiratory tract and dermal irritation when humans are exposed by inhalation to sufficiently high concentrations. In the past, 1,1-dichloroethane was used as an anesthetic; however, this use was discontinued due to the risk of induction of cardiac arrhythmia in humans. Crystal precipitations and obstruction in the renal tubule lumina and increases in serum urea and creatinine were observed in cats exposed to this compound for weeks. However, these effects were not observed in rats, guinea pigs, or rabbits. However, kidney effectswere observed inmice administered a lethal intraperitoneal injection; the effects included increased glucose and protein in the urine and tubular swelling. The toxicological significance of the nephrotoxicity observed in cats and the mice with regard to human health is not known given the small number of animals tested (cats).The detectionof 1,1-dichoroethane or itsmetabolites in blood and urine cannot predict the type of health effects that might develop from that exposure; because 1,1-dichloroethane and its metabolites leave the body fairly rapidly, the tests need to be conducted within hours to days after exposure.

Chemical properties

Also ethylidene chloride,CH3CHCl2 is a colorless,neutral,mobile liquid with an aromatic ethereal odor and saccharin taste. Soluble in alcohol, ether,fixed and volatile oils and very sparingly soluble in water. It is used as an extraction solvent and fumigant.

Physical properties

1,1-Dichloroethane is a clear, colorless, oily liquid with a chloroform-like odor. It is more polar than trans but less polar than cis form.Two chlorine atoms are not on the same side of the plane,hence the net dipole is going to be lesser than cis form.

The Uses of 1,1-Dichloroethane

1,1-Dichloroethane is used as a chemical solvent in the preparation of precursors of quinolizine, isoquinoline and indole alkaloids.

The Uses of 1,1-Dichloroethane

Solvent for paint, varnishes; degreaser. Has been used as a surgical anesthetic.

The Uses of 1,1-Dichloroethane

Ethylidene dichloride is primarily used as an intermediate in chemical synthesis. Acute (short-term) inhalation exposure to high levels of ethylidene dichloride in humans results in central nervous system (CNS) depression and a cardiostimulating effect resulting in cardiac arrhythmias. Studies in animals have reported effects on the kidney. No information is available on the chronic (long-term) reproductive, developmental, or carcinogenic effects of ethylidene dichloride in humans. An oral animal study reported a significantly positive dose-related trend in hemangiosarcomas, mammary tumors, liver tumors, and endometrial stromal polyps. EPA has classified ethylidene dichloride as a Group C, possible human carcinogen.
Primary uses are:
Ethylidene dichloride is primarily used as an intermediate in the manufacture of other chemicals such as vinyl chloride and 1,1,1- trichloroethane, and to manufacture high vacuum rubber.
Ethylidene dichloride has limited use as a solvent for plastics, oils, and fats.
In the past, ethylidene dichloride was used as an anesthetic, but that use has been discontinued.
Ethylidene dichloride is a colorless oily liquid which is very volatile. It has an odor similar to ether; the odor threshold is 120 parts per million (ppm).

Definition

ChEBI: 1,1-Dichloroethane is an organochlorine compound.

General Description

A colorless liquid with an ether-like odor. Slightly soluble in water and slightly denser than water. Flash point below 70°F. Vapors denser than air. Used to make other chemicals.

Air & Water Reactions

Highly flammable. Slightly soluble in water.

Reactivity Profile

1,1-DICHLOROETHANE can react vigorously with oxidizing materials. 1,1-DICHLOROETHANE is incompatible with strong bases. Contact with strong caustics will cause formation of flammable and toxic gas. 1,1-DICHLOROETHANE will attack some forms of plastics, rubber and coatings.

Hazard

Toxic. Eye and upper respiratory tract irritant; kidney and liver damage. Questionable carcinogen.

Health Hazard

INHALATION: Irritation of respiratory tract. Salivation, sneezing, coughing, dizziness, nausea, and vomiting. EYES: Irritation, lacrimation, and reddening of conjunctiva. SKIN: Irritation. Prolonged or repeated skin contact can produce a slight burn. INGESTION: Ingestion incidental to industrial handling is not considered to be a problem. Swallowing of substantial amounts could cause nausea, vomiting, faintness, drowsiness, cyanosis, and circulatory failure.

Safety Profile

Moderately toxic by ingestion. Experimental teratogenic effects. Questionable carcinogen with experimental tumorigenic data. Liver damage reported in experimental animals. A very dangerous fire hazard and moderate explosion hazard when exposed to heat or flame; can react vigorously with oxidizing materials. To fight fire, use alcohol foam, water, foam, CO2, dry chemical. When heated to decomposition it emits highly toxic fumes of phosgene and Cl-

Potential Exposure

It is used as a solvent; cleaning and degreasing agent; as well as in organic synthesis as an 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. If victim is conscious, administer water ormilk. Do not induce vomiting.

Carcinogenicity

The EPA 2010 classifies 1,1- dichloroethane in group C, a possible human carcinogen, based on no human data and limited evidence of carcinogenicity in two animal species (rats and mice) as shown by an increased incidence of mammary gland adenocarcinomas and hemangiosarcomas in female rats and an increased incidence of hepatocellular carcinomas and benign uterine polyps in mice. The EPA offers no estimate of carcinogenic risk from inhalation or oral exposure. The EPA states (IRIS) that because of similarities in structure and target organs, the carcinogenic evidence for 1,2-dichloroethane is supportive of the classification of 1,1-dichloroethane in group C, a possible human carcinogen. The EPA considers the animal carcinogenicity “limited.”

Environmental Fate

Biological. 1,1-Dichloroethane showed significant degradation with gradual adaptation in a static-culture flask-screening test (settled domestic wastewater inoculum) conducted at 25 °C. At concentrations of 5 and 10 mg/L, percent losses after 4 wk of incubation were 91 and 83, respectively. At a substrate concentration of 5 mg/L, 19% was lost due to volatilization after 10 d (Tabak et al., 1981). Under anoxic conditions, indigenous microbes in uncontaminated sediments produced vinyl chloride (Barrio-Lage et al., 1986).
Surface Water. The following volatilization half-lives were reported for 1,1-dichloroethane: 6 to 9 d in a pond, 5 to 8 d in a lake, 24 to 32 h in a river (Smith et al., 1980).
Photolytic. Titanium dioxide suspended in an aqueous solution and irradiated with UV light (λ = 365 nm) converted 1,1-dichloroethane to carbon dioxide at a significant rate (Matthews, 1986). The initial photodissociation product of 1,1-dichloroethane was reported to be chloroacetyl chloride (U.S. EPA, 1975). This compound is readily hydrolyzed to HCl and chloroacetic acid (Morrison and Boyd, 1971).
The rate constant for the reaction of 1,1-dichloroethane and OH radicals in the atmosphere at 300 K is 1.6 x 10^-11 cm³/molecule?sec (Hendry and Kenley, 1979). At 296 K, a photooxidation rate constant of 2.6 x 10^-13 cm³/molecule?sec was reported for the reaction with OH radicals resulting in a half-life of 1.5 months (Howard and Evenson, 1976).
Chemical/Physical. A glass bulb containing air and 1,1-dichloroethane degraded outdoors to carbon dioxide and HCl. The half-life for this reaction was 17 wk (Pearson and McConnell, 1975). Hydrolysis of 1,1-dichloroethane under alkaline conditions yielded vinyl chloride, acetaldehyde, and HCl (Kollig, 1993). The reported hydrolysis half-life at 25 °C and pH 7 is 61.3 yr (Jeffers et al., 1989).

storage

Color Code—Red: Flammability Hazard: Store ina flammable liquid storage area or approved cabinet awayfrom ignition sources and corrosive and reactive materials.Prior to working with this chemical you should be trainedon its proper handling and storage. Before entering confinedspace where this chemical may be present, check to makesure that an explosive concentration does not exist. 1,1-Dichloroethane must be stored to avoid contact with strongoxidizers, such as chlorine, bromine, and fluorine, sinceviolent reactions occur. Store in tightly closed containers ina cool, well-ventilated area away from heat. Sources ofignition, such as smoking and open flames are prohibitedwhere 1,1-dichloroethane is used, handled, or stored in amanner that could create a potential fire or explosion hazard. Metal containers used in the transfer of=gallons ormore of 1,1-dichloroethane should be grounded and bonded.Drums must be equipped with self-closing valves, pressurevacuum bungs, and flame arresters. Use only nonsparkingtools and equipment, especially when opening and closingcontainers of 1,1-dichloroethane.

Shipping

UN2362 1,1-Dichloroethane, Hazard Class: 3; Labels: 3-Flammable liquid

Purification Methods

Shake it with conc H2SO4 or aqueous KMnO4, then wash it with water, saturated aqueous NaHCO3, again with water, dry with K2CO3 and distil it from CaH2 or CaSO4. Store it over silica gel. [Beilstein 1 IV 130.]

Toxicity evaluation

Production and use of 1,1-dichloroethane as a chemical intermediate, in paint removers, and as a antiknock gasoline additive may result in its release to the environment through various waste streams. If released to air, it will exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,1-dichloroethane will be degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals (estimated half-life, 49 days). 1,1-Dichloroethane when released to soil is expected to have very high mobility based on a Koc of 30. Volatilization from moist soil surfaces is expected to be an important fate process of this compound. 1,1-Dichloroethane may volatilize from dry soil surfaces based on its vapor pressure. Halogenated aliphatic hydrocarbons are generally considered to be resistant to biodegradation. However, in water, 1,1-dichloroethane is not expected to adsorb to suspended solids and sediments based on the Koc. Estimated volatilization half-lives for a model river and model lake are 3 h and 4 days, respectively. An estimated bioconcentration factor of 5 suggests the potential for bioconcentration in aquatic organisms is low. The environmental hydrolysis half-life at 25°C and pH 7 is 61 years.

Incompatibilities

Vapor may form explosive mixture with air. Reacts violently with strong oxidizers, alkali metals; earth-alkali metals; powdered metals; causing fire and explosion hazard. Contact with strong caustic will produce flammable and toxic acetaldehyde gas. Attacks aluminum, iron. Attacks some plastics (including polyethylene) and coatings.

Waste Disposal

Incineration; preferably after mixing with another combustible fuel. Care must be exercised to assure complete combustion to prevent the formation of phosgene. An acid scrubber is necessary to remove the halo acids produced. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal