Chloroform and Phosgene Generation

The material from this module is taken from the US Department of Commerce/NOAA.

Chloroform is used in many organic extraction methods in molecular biology.  It is recommended that it is stored in a dark place in an amber bottle and used only in a vented fume hood.  Phosgene (used as a war gas in WWI) is a breakdown product of chloroform.  Phosgene exposure can cause damage to the central nervous system in concentrations at only a small fraction of the permissible exposure limit of chloroform.  Chloroform, stabilized with alcohol, should be purchased in the future whenever possible.  If non-stabilized chloroform is necessary for the work, it needs to be treated like peroxide forming compounds and be used up in a short amount of time.  Amylene is also used as a stabilizer, but there is evidence that it may not prevent phosgene generation.  Any unstabilized chloroform older than one year; it should be discarded as hazardous waste.  Submit an online Hazardous Waste Pickup Request. Go here to learn how or call 474-5617 or 474-5197

Lockheed Martin Idaho Technologies Company also suggests the following:

  1. Unless program requirements prohibit it, chloroform that is stabilized with alcohol should be purchased in the future.  Alcohol is usually added in greater concentrations than amylene so it provides better protection from phosgene generation. Also, there is evidence that amylene may not prevent phosgene generation.
  2. Chloroform should be treated as a time-sensitive chemical.  This is especially true of chloroform that is either not stabilized or is stabilized with amylene.
  3. Call EHSRM at 474-5617 before using a container of chloroform that is six months old or older so the presence of phosgene can be tested.