1,2-Dichloroethane is a solvent used in food processing.The chemical compound 1,2-dichloroethane, commonly known by its old name of ethylene dichloride (EDC), is a chlorinated hydrocarbon, mainly used to produce vinyl chloride monomer (VCM, chloroethene), the major precursor for PVC production. It is a colourless liquid with a chloroform-like odour. 1,2-Dichloroethane is also used generally as an intermediate for other organic chemical compounds, and as a solvent.
1,2-Dichloroethane belongs to the family of Organochlorides. These are organic compounds containing a chlorine atom.
belongs to the class of organic compounds known as organochlorides. Organochlorides are compounds containing a chemical bond between a carbon atom and a chlorine atom.
1,2-Dichloroethane is metabolized to 2-chloroacetaldehyde, S-(2-chloroethyl)glutathione by conjugation with glutathione, and to other putative reactive intermediates capable of binding covalently to cellular macromolecules in the liver, kidney, and other tissues. The conjugation of 1,2-dichloroethane with glutathione is catalyzed primarily by glutathione S-transferases. 1,2-Dichloroethane appears to be activated to mutagenic species to a lesser extent by the hepatic microsomal cytochrome P-450 enzyme system. Reactive metabolites of 1,2-dichloroethane produced by hepatic microsomal cytochrome P-450 can bind to cellular proteins and DNA. It has been suggested that 1,2-dichloroethane-induced toxicity occurs when the biotransformation processes are saturated, thereby allowing higher levels of 1,2-dichloroethane to circulate throughout the body and conjugate with glutathione instead of being detoxified and eliminated. (5, 1)
Metabolism
Due to its physical properties such as its lipophilicity, 1,2-dichloroethane is likely to be absorbed across the alveolar membranes of the lung, mucosal membranes of the gastrointestinal tract, and the skin by passive diffusion. Once in the body, it is widely distributed, with the greatest amounts accumulating in the more lipophilic tissues. The primary route of biotransformation involves conjugation with glutathione to yield nonvolatile urinary metabolites. The other route, a cytocrome P-450-mediated oxidation is responsible for the formation of chloroacetaldehyde. Metabolic saturation appears to occur sooner after oral (gavage) administration than after inhalation exposure. Following inhalation or oral exposure, elimination of 1,2-dichloroethane occurs primarily via excretion of soluble metabolites in the urine and excretion of unchanged parent compound and carbon dioxide in the expired air. (5)
The most common use of 1,2-dichloroethane is in the production of vinyl chloride which is used to make a variety of plastic and vinyl products including polyvinyl chloride (PVC) pipes, furniture and automobile upholstery, wall coverings, housewares, and automobile parts. It is also used as a solvent and is added to leaded gasoline to remove lead. Exposure occurs mainly by breathing air or drinking water contaminated with 1,2-dichloroethane. Humans can be exposed to low levels of 1,2-dichloroethane through the skin or air by contact with old products made with 1,2-dichloroethane. (5)
Breathing or swallowing large amounts of 1,2-dichloroethane can produce nervous system disorders, kidney diseases, or lung effects. This can also lead to heart failure. Skin lesions and benign pulmonary tumors were reported in animals exposed dermally to liquid 1,2-dichloroethane. 1,2-dichloroethane can cause death from cardiac arrhythmia, bronchitis, hemorrhagic gastritis and colitis, hepatocellular damage, renal tubular necrosis and calcification, central nervous system depression, and histological changes in brain tissue after a sufficient single oral dose. (5)
Symptoms
1,2-Dichloroethane exposure causes abdominal pain, coughing, dizziness, drowsiness, headache, nausea, sore throat, diarrhea, unconsciousness, and vomiting, depending on the contact surface and the intensity. Redness of the eyes or skin occurs upon contact. (6)
Treatment
Blood gases should be monitored, a good ventilation maintained, and cardiac arrhythmias observed for a minimum of 24 hours. In the event of a ventricular arrhythmia, lidocaine or beta-blockers could be administered. Serum creatinine, hepatic aminotransferase, electrolytes, and fluid balance for signs of hepatic or renal failure should be monitored. Dialysis may be helpful in the event of renal failure. Hepatic failure may be treated with fresh frozen plasma, vitamin K, low protein diet, neomycin, and lactulose. (5)
