On Wednesday, February 14, 2018 at 10:52:20 AM UTC-5, Larry Jaques wrote:
On Tue, 13 Feb 2018 20:50:03 -0600, Ignoramus14057
wrote:

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.

Regulations or not, some oil additives or contaminants may end up making nasty fumes that you may end up breathing. Lab tests for oils are cheap - $28 from this place https://www.blackstone-labs.com/standard-analysis.php I'm sure you could find a place in the Chicago area to do it, and then you'll know for sure what you have.