Spontaneous combustion is real and can be a big problem. It can occur
without the material being volatile.

My experience with spontaneous combustion occured when we had our
hardwood floors refinished. We had just moved into the house and had a
garage full of cardboard boxes, some full of things, and others broken
down and stacked. The people who were refinishing the floors placed the
sanding dust in a bag in a garbage can in the garage. My wife was in
the family room and smelled smoke. When I went into the garage it was
filled with smoke. Fortunately I was there when it occured and was able
to get the can out of the garage and get the fire extinguished. The
only loss was the garbage can.

I have often wandered what could have occured.

Me wrote:
In article ,
"Roger Long" wrote:


We all grew up hearing about the danger of oily rags. It was linseed
oil they were talking about, not motor oil. Now that I (hopefully)
will be rubbing oil on teak for the rest of my natural life, I expect
to producing a lot of these little incendiary bombs.

How much of a danger are these left over rags? Is it something that
happens just once in a blue moon when a bunch are left in the corner
of a shop for a long time in hot weather? If the phone rings and I
forget to take one to the dumpster, is it "Good by" boat? If I do
toss them in the dumpster, am I at risk of starting a big fire in my
favorite marina or boatyard.

Is there an approved way of storing or disposing of linseed oil rags?

Inquiring mind wants to know.


From a chemist's point of view, it is a danger, but not a significant
one in most circumstances. Spontainious Combustion can, and does, occure
with oily rags, stacked in a pile, with little or no airflow, where heat
can build up, due to chemical breakdown of the adsorbing material, by
properties in the oils adsorbed. It is a fairly rare occurance, mostly
due to folks having been told, many times, of the possibilities, and
keeping things cleaned up. Flashpoint Temps for most oils are fairly
high and the required heat buildup doesn't happen, but if conditions are
right, Yea it can be a BIG Deal.....

Me a NitroOrganic Chemist, in a past life.......