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From a chemical reactivityperspective there is no reason why one should not store chloroogenated hydrocarbons away from other flammable liquids. As far as I know, there are no chemical vapors that would lead to the generation of phosgene gas. You are correct that heat will convert chloroform and carbon tetrachloride into phosgene gas, but this has in some cases led people to become confused from historical prejudices. Long back before modern firefighting equipment came out carbon tetrachloride was packaged in glass spheres about the size of a softball. When firemen aproached a fire, they would throw the sphere at the fire which would break releasing the chloroform. The chlorofrom would help smother the flames and put the fire out,but the smoldering fire would generate phosgene which would, in turn, killthe firemen. Because of this,old time firemen I have worked with have told me that one should not store chloroform or carbontetrachloride with other flammable liquids. What is interesting is that the phosgene is generated most readily at around 300-350C and then thermally decomposes at more elevated temperatures (Unfortunately I no longer have a referencefor this).
From a regulatory situation, the situation is alot more clear. There are no regulations requiring nonflammable chloronated hydrocarbons like choroform to be stored inside flammable cabinets, although some fire protection people get upset if they are stored that way. If the chloronated hydrocarbon meets the definition of a Class IIIB combustible liquid(flash point greater than 200F)
then one may store the liquid inside the flammable cabinet, but thereis no regulation to do so. All chloronated hydrocarbons with a flashpoint at or below 200F (Class IA,B, C flammable, Class II and IIIA combustible liquids) are required to be stored in a flammable cabinet unless you can demonstrate that you are below de minimu quantites per fire area. (You should best conslt a fire protection person to make the determination of the last sentence.)
I hope this makes sense.
Dave Quigley, Ph.D.
3319 Miller Creek Road
Knoxville, TN 37931
-----Original Message-----
From: Peifer, Patricia <Patricia.Peifer**At_Symbol_Here**WESTPHARMA.COM>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Sent: Thu, Oct 27, 2011 11:58 am
Subject: [DCHAS-L] Storage of Chlorinated Solvents and Flammables
All,
I have asked our staff to store chlorinated solvents separately from flammable
substances. I know that this is generally good practice, but I also read that
some chlorinated solvents can react with some flammables to produce phosgene,
and perhaps other toxic gases as well. This made some sense to me since I know
chlorinated solvents can produce these gases when exposed to heat or UV.
I am being challenged on this and asked to produce the names of flammables that
will react with chlorinated solvents upon contact to produce dangerous gases.
Does anyone have information on this? Are there other compelling reasons not
to store chlorinated solvents with flammables?
Thanks,
Pat
Pat Peifer, CHO
Safety and Chemical Hygiene Specialist
West Pharmaceutical Services
101 Gordon Drive
Lionville, PA 19341
Find West on Twitter <http://twitter.com/#!/WestPharma> and LinkedIn<http://www.linkedin.com/company/west-pharmaceutical-services?trk=fc_badge>.
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