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Re: Parts/Dish Washer Machine

To: Shop Talk <shop-talk@Autox.Team.Net>
Subject: Re: Parts/Dish Washer Machine
From: Douglas Shook <dshook@usc.edu>
Date: Tue, 07 Jul 1998 15:47:27 -0700
Yes, the flash point does sound low, but what it actually is telling us
is that we could put a match directly into the solvent if the
temperature of the solvent is less than 110 degrees, the match would go
out. Many solvents are rated at 105 F or less. Gasoline and acetone's
flash points are less than 73 F (I have some of both out in the garage).

Even in the South, chances are the actual temperature of the solvent
would not reach 110 F (should take several days when the average 24 hour
temperature is well above 110 F).  At a solvent temperature of 109 F, we
still should be able to put out cigars in the parts washer.  Agitene at
110 F is not considered "flammable," only "combustable," like heating
oil or diesel.

In comparison, the flash point for ethyl alcohol (Scotch) is 55 F---be
careful smoking that cigar with your scotch! I'm attaching a summary I
grabbed from the web.

doug
-----------------------------------------------------------

Flash Point

               A fire will not occur until a flammable liquid is
               heated above a certain temperature called the
               flash point. Put more scientifically, flash point is
               the lowest temperature at which a liquid gives off
               enough vapor to cause a momentary flame in the
               presence of an ignition source.

               In general, the lower the flash point, the greater
               the hazard. If the liquid's temperature is below the
               flash point, it simply will not give off enough
               vapor to burn. For example, the flash point of one
               of my favorite compounds, ethyl alcohol, is 55 F.
               If we put a lighted match into an ice-cold glass of
               Scotch or Brandy, the match would go out.
               However, when the glass warms up to a little over
               55 F, the vapors formed at the mouth of the glass
               would ignite if the match is brought close to the
               edge.


               Liquid Classes

               Flash point and boiling point are important to
               know because they are used as the basis for
               identifying liquids that present a similar degree of
               hazard. Those chemicals with flash points less
               than 100 F are referred to as flammable liquids,
               while those with flash points greater than, or
               equal to 100 F, are called combustible liquids.

               Flammable and combustible liquids can be further
               divided into classes. Class I-A flammable liquids
               are those with flash points less than 73 F, and
               boiling points less than 100 F. Ethyl ether,
               pentane, and ethylene oxide are examples of Class
               I-A materials.

               Class I-B flammable liquids include materials like
               acetone, cyclohexane, and gasoline that have flash
               points less than 73 F and boiling points at or above
               100 F. Class I-C flammable liquids are solvents
               like butyl alcohol, turpentine, and xylene with
               flash points between 73 F and 100F.

               Class II combustible liquids are those with a flash
               point above 100 F but below 140 F. Kerosene,
               diesel fuel, and No. 2 heating oil are familiar
               examples. Class III-A combustible liquids have a
               flash point between 140 F and 200 F and include
               acetophenone, diethyl benzene, and isopherone.
               Class III-B are those with a flash point greater
               than 200 F and include many natural oils like
               castor oil, olive oil, and peanut oil.

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