Dichloromethane (DCM)

2020-06-19

Dichloromethane (DCM)—also known as methylene chloride—is a clear colourless liquid. It is highly volatile and has a sweet smell. It has been classified as a Category 3 carcinogen: possibly carcinogenic, but without adequate information to make that assessment. [1,2]

Uses [1]

Dichloromethane is used across various industries, primarily as a solvent. It is used a solvent in paints and varnish strippers, and as an extraction solvent in the food and drink industry. For example, the chemical can be used to remove caffeine from tea and coffee. Industrially, it is used in the production of pharmaceuticals, paint strippers and process solvents. The liquid is also used in the transport industry to degrease metal surfaces and parts. In the medical world, dichloromethane is used in cleaners and to extract chemicals from plants or food for medicinal uses.

Routes of Exposure [2]

The primary route of exposure to dichloromethane is via inhalation.

People can also be exposed to the chemical through ingestion and skin contact.

Health Effects

Dichloromethane poisoning affects a range of systems including the integumentary and nervous systems.

Acute Effects [2]

Severity of symptoms depend on the level and type of exposure.

Acute exposure to the chemical can result in CNS depression, which can result in headaches, drowsiness, light-headedness, slowed reaction times, irritability, impaired gait, stupor, and slurred speech.

Prolonged skin contact to the chemical may cause chemical burns.

Exposure to dichloromethane can cause airway irritation, accumulation of fluid in the lungs, and inflammation of the lungs.

Exposure can result in nausea, vomiting, bleeding and gastrointestinal ulceration.

It can also result in sequelae.

Chronic Effects [2,4]

Dichloromethane is toxic to multiple body systems. Long-term exposure to the chemical can result in irritant contact dermatitis, respiratory irritation and gastrointestinal problems. It can also result in long-term neurological issues, including paraesthesia.

Safety

~h2First Aid Measures [5]

  • Ingestion: DO NOT INDUCE VOMITING. Rinse victim’s mouth with water. Immediately contact a medical professional.
  • Skin contact: Avoid direct contact with the chemical, and wear protective clothing if necessary. Remove all contaminated clothing, footwear and accessories. Rinse victim with lukewarm water for 15-20 minutes. Immediately contact a healthcare professional.
  • Eye contact: Immediately rinse eyes for 15-20 minutes with gently flowing lukewarm water. Hold the victim’s eyelids open to ensure they are thoroughly flushed. If pain or irritation persists, contact a medical professional.
  • Inhalation: Take victim to the nearest fresh air source and monitor their breathing. Immediately contact a medical professional. 
  • General: Never administer anything by mouth to an unconscious, exposed person.

  • Exposure Controls/Personal Protection [5]

  • Engineering controls: Emergency eyewash fountains and safety showers should be accessible in the immediate area of the potential exposure. Ensure there is adequate ventilation. Use a local exhaust ventilation to limit the amount of dichloromethane in the air.

  • Personal protection: Safety glasses, protective and dustproof clothing, gloves, an apron and an appropriate mask. Follow the PPE guidelines set in your jurisdiction. 

Regulation [6]

~h2United States:

The Occupational Safety and Health Administration (OSHA) has set an 8-hour time weighted average (TWA) concentration limit for dichloromethane of 25ppm.

Australia [7]

Safe Work Australia has set an 8-hour time TWA for dichloromethane of 50ppm.

References

https://www.chemicalsafetyfacts.org/methylene-chloride/

https://www.atsdr.cdc.gov/MMG/MMG.asp?id=230&tid=42#:~:text=Methylene%20chloride%20exposure%20causes%20dose,%2C%20impaired%20gait%2C%20and%20stupor.

https://www.sciencedirect.com/science/article/pii/S2211558716300231

http://www.inchem.org/documents/pims/chemical/pim343.htm#PartTitle:5.%20%20ROUTES%20OF%20ENTRY

https://www.ccohs.ca/oshanswers/chemicals/chem_profiles/methylene.html

https://www.cdc.gov/niosh/npg/npgd0414.html

http://hcis.safeworkaustralia.gov.au/ExposureStandards/Document?exposureStandardID=401