Dichloromethane

(USAN, rINN)
Dichloromethane Chemical formula
Synonyms: Cloruro de metileno; Dichlormethan; Diclorometano; Diklórmetán; Methylene Chloride; Méthylène, chlorure de; Methyleni chloridum; Metileno chloridas; Metyleenikloridi; Metylenklorid; Metylenu chlorek.
Cyrillic synonym: Дихлорметан.

💊 Chemical information

Chemical formula: CH2Cl2 = 84.93.
CAS — 75-09-2.

Pharmacopoeias.

In Eur.. Also in USNF.

Ph. Eur. 6.2

(Methylene Chloride; Dichloromethane BP 2008). A clear, colourless, volatile liquid. Relative density 1.320 to 1.332. It may contain not more than 2% of alcohol and/or not more than 0.03% of 2-methylbut-2-ene as stabiliser. Sparingly soluble in water; miscible with alcohol. Store in airtight containers. Protect from light.

USNF 26

(Methylene Chloride). A clear, colourless, mobile liquid having an odour resembling chloroform. Sp. gr. 1.318 to 1.322. Miscible with alcohol, with ether, and with fixed and volatile oils. Store in airtight containers.

Stability.

Phosgene is produced on heating of dichloromethane.

💊 Adverse Effects and Treatment

Acute exposure to dichloromethane vapour may depress the CNS; symptoms progress from headache and dizziness to coma and death in severe cases. Pulmonary oedema has been reported. Significant exposure may result in raised blood concentrations of carboxyhaemoglobin and symptoms of carbon monoxide poisoning. Cardiovascular effects have been attributed to hypoxia secondary to carboxyhaemoglobinaemia. There has been a report of haemolysis after acute ingestion of dichloromethane. Chronic occupational exposure to dichloromethane vapour has produced gastrointestinal disturbances in addition to symptoms observed after acute poisoning. Dichloromethane is a common constituent of paint strippers and may be implicated in volatile substance abuse. The liquid is irritant and high concentrations of the vapour are irritant to the eyes. Treatment of acute poisoning consists of removal from exposure and supportive and symptomatic measures. Carboxyhaemoglobinaemia should be managed as for carbon monoxide poisoning by giving 100% oxygen; hyperbaric oxygen may be indicated. After ingestion gastric lavage or activated charcoal are generally contra-indicated, although gastric aspiration may be considered in serious cases if the airway can be protected. Adrenaline and other sympathomimetics should also be avoided because of the risk of precipitating cardiac arrhythmias.
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32. Geneva: WHO, 1984. Available at: http://www.inchem.org/ documents/ehc/ehc/ehc32.htm (accessed 29/06/04
2. Health and Safety Executive. Dichloromethane (methylene chloride). Toxicity Revie
12. London: HMSO, 1985
3. WHO. Methylene chloride health and safety guide. IPCS Health and Safety Guid
6. Geneva: WHO, 1987. Available at: http:// www.inchem.org/documents/hsg/hsg/hsg006.htm (accessed 29/06/04
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5. Manno M, et al. Double fatal inhalation of dichloromethane. Hum Exp Toxicol 1992; 11: 540–5
6. Dhillon S, Von Burg R. Methylene chloride. J Appl Toxicol 1995; 15: 329–35
7. Chang YL, et al. Diverse manifestations of oral methylene chloride poisoning: report of 6 cases. J Toxicol Clin Toxicol 1999; 37: 497–504
8. Jacubovich RM, et al. Facial nerve palsy after acute exposure to dichloromethane. Am J Ind Med 2005; 48: 389–92.

💊 Pharmacokinetics

Dichloromethane is rapidly absorbed after inhalation and is also absorbed after ingestion and slowly through intact skin. It appears to be partially metabolised to carbon dioxide and carbon monoxide which are exhaled, although significant blood-carboxyhaemoglobin concentrations may be attained. Some unchanged dichloromethane is exhaled and small amounts are excreted in the urine.

💊 Uses

Dichloromethane is used as a pharmaceutical and industrial solvent. It is also employed as an extraction solvent in food processing. Dichloromethane is widely used in paint strippers.
Published October 21, 2018.