• Mercury poisoning of researcher at Dartmouth College (Chem & Engineering News May 12, 1997 and Athens News, Lyme, NH, Sept 1997

• Cutting Christmas trees safely (from Southwest Lawn & Garden December 1997)

• Tips on pesticide use around the home (from the City of Las Cruces and the NMSU/Dona Ana Cooperative Extension Service)

• Caution - Phosgene hazard from chloroform (posted April 2000)

Hazard

Researchers at the University of California, Los Angeles became ill after using a three-year-old bottle of chloroform.  Analysis of the chloroform revealed concentrations of 15,000 ppm of phosgene in the headspace of the bottle and 1.1% concentration of phosgene in the bulk solution.
While most material safety data sheets (MSDS) warn that phosgene may be generated from chloroform when exposed to flames, electrical arcs, intense sunlight or hot surfaces. they do not mention that phosgene may be generated over time from prolonged storage. The incident at UCLA suggests that chloroform can break down and form phosgene in older containers.
Brief exposures (1 to 2 minutes) to 20 ppm phosgene can cause severe lung injury, and higher concentrations can cause death from pulmonary edema. Initial symptoms of exposure include throat irritation, coughing, chest pain, nausea and difficulty breathing. Severe symptoms such as extreme difficulty breathing may appear one to twenty-four hours after exposure.
Precaution
As chloroform is used in laboratories on campus, researchers using this compound should follow these precautions:
• Purchase stabilized chloroform whenever possible. Amylene, a common stabilizer, will reduce, but not prevent, the generation of phosgene.
• If unstabilized chloroform is needed, treat it as a time-sensitive chemical similar to ether;
  • date when received;
  • date when opened; and
  • discard within one year.
• Store chloroform in a dark place (cabinet) in an amber bottle to reduce rate of decomposition.
• Open chloroform containers in a chemical fume hood and use it in the fume hood as much as possible.
• If you have opened unstabilized chloroform or chloroform stabilized with amylene that has been in the laboratory for more than one year, it is in your best interest to dispose of it as hazardous waste.
If you have any questions regarding the handling of hazardous materials on campus, call Environmental Health and Safety at 646-3327.
(Adapted from the Indiana University 'Safety Bulletin', January 2000 and Yale University "Safety Bulletin" January 1999) - dls April 00.

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