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Ethers are a class of organic compounds that contain an ether group and are flammable.

Why this substance is hazardous

  • Ethers are flammable, diethyl ether (C2H5)2O is classified as extremely flammable.​
  • Ethers only require a hot surface such as hot plate, steam pipes, lamp bulbs or a static electrical discharge to easily ignite. A mobile phone could be an ignition source.​
  • Ether can form an explosive atmosphere with air at the concentration between 1.9 – 36% (by volume) ​
  • Ethers rarely cause long term damage to the skin and eyes, but contact can cause irritation symptoms.​
  • Inhalation in high concentration can cause, inebriation, sedation, lead to unconsciousness and respiratory paralysis​.


Ethers are most commonly used as anaesthetic and solvents​.

Recommended Control Measures​

Avoiding an explosive atmosphere. As the lower explosive limit is 1.9%, even working within a fume cupboard cannot guarantee that an explosive atmosphere cannot be created. Therefore additional precautions need to be taken​.

  • If possible the fume cupboard or work area should be designed for working with an explosive atmosphere (electrical appliances to be rated under ATEX)​.
  • The work area to be cleared of all heat sources, no hot plate, water baths, including personal equipment such as phones and chargers.​
  • Part of the risk assessment will be to agree with the person in charge of the lab and other lab users the amount of ether that can be stored, used or produced in the area. This has to be approved by the Head of Department.​
  • Ethers will form unstable peroxides over time (commercially supplied diethyl ether has additives to inhibit this). The risk assessment must propose a procedure for monitoring all stored ethers for the production of peroxides and steps put in place to inhibit the production and to manage disposal if the formation is detected.  ​

Health Surveillance ​

Diethyl ether is classed as having adequate warning properties and has been assigned a Workplace Exposure Limit (WEL) of: 

  • 100ppm Long-Term-Exposure Limit (8hr TWA reference period)
  • 200ppm Short-Term-Exposure Limit (15 minute reference period)

There must be a system in place to ensure the WELs are not reached or exceeded.

Chemical safety library

> Read more about control measures for chemicals in our chemical safety library 

Interesting fact

On 1st June 1958 a railroad tanker containing nitromethane exploded, the cause was thought to be due to adiabatic pressure (air bubbles compressing and superheating due to a rise in pressure) – This risk is common to all liquid explosives.

Last updated: Monday, June 7, 2021