Jim Robinson wrote:

>applications where there are large quantities of metal shavings. He
>suggested that we consider purchasing the class D agent in 5 gal.
>plastic buckets commonly used by extinguisher service companies to
>refill extinguishers. Add a scoop and the researchers can simply
>shovel this onto a small fire. It's about 20% of the cost of an
>extinguisher and doesn't need to be recharged after each use. Any
>thoughts from the list??
>
>Jim Robinson
>Univ of Maryland


We've got a couple of the class D extinguishers on campus but most
labs just have the 5 gallon buckets of class D agent with a  metal
scoop.  Years ago someone fabricated some wooden signs to fit on top
of the buckets (round wood disk to fit into the top of the bucket lid
with a flat board sticking straight up from the disk.  All painted
red with a fire extinguisher sign mounted on the flat board.).

For the most part, the fires I've seen involving combustible metals
in chemistry labs involve small amounts of metal.  The typical
scenario is when a glass container of solvent and air/water reactive
metal is broken on a lab bench.  When the metal is exposed to the air
it ignites the solvent.  Most folks put it out with a CO2
extinguisher (though in many cases I suspect the solvent just burns
away before they can get it out) and then clean up and dispose of the
metal using normal lab techniques.

The other type of fire I've seen involves ordinary combustibles
(usually in a trash can) that are ignited by an air/water reactive
metal.  We've had cases where someone wipes off a scalpel with a
tissue after cutting a metal such as sodium  and just tosses the wipe
into the trash can.  As a result, all chemistry building labs are now
supposed to have metal trash cans with tight fitting lids to help
reduce the chances of this type of fire.  Ironically, that was
determined to be the cause of our last major chem lab fire but the
major water damage was not from sprinklers (there were none in that
room) but from the fire damaged domestic water pipes from under the
lab bench.  We had water running through 3 floors of the building
including the chemical stockroom but had no problems with water
getting into any reactive chemicals.
--

DANIEL MAAS      (607)254-1634     FAX: (607)255-1642
Emergency Management Coordinator/Event Management Coordinator
Fire Protection & Emergency Services
Cornell University Environmental Health & Safety
EH&S Bldg,  201 Palm Road, Ithaca, NY  14850
email: [log in to unmask]

******************Disclaimer*************************
The comments and views expressed in this communication are
strictly my own and are not to be construed to officially represent
those of my peers, supervisors or Cornell University