I bought a very large geat cutting machine for scrap. This machine is
sitting in a pit full of oil. I spoke to the person who maintained it
and he says that the oil is only lube oil and NOT cutting oil.

I have a oil fired furnace Clean Burn CB2800. I burn all my oil,
mostly used hydraulic oil, in it to save on natural gas costs. The
instruction to the furnace says "DO NOT USE CUTTING OIL". I am not
sure why exactly, either the furnace will be damaged or due to
environmental regulations.

Someone else from the company said that cutting oil "might" be in it.

How can I tell? Is smell a good enough indicator? Is there any easy
test that I can subject the oil to?

I am talking at least a ton of oil if not several tons. And I need all
that oil if I can burn it.

Thanks