Overheated oil and it's exposure limits

Generally this type of oil(140 grade)have very high flash point,like more than 250°c etc...So fumes will comes only when it is subjected to higher temperature,say more than 100 or 150 °c.So please look into the temperature first.

Gasbo,

Normally in the material safety data sheet for the product, there is an exposure limit to oil mist quoted. You should be able to obtain this from the oil supplier.

Being an underground mine, you should consult your OHS dept to work out exposure levels.

Thanks for the info. I did contact our OH&S guy. In the MSDS there is a section on Composition and Ingredients: and gives you a CAS (Chemical Abstract Service Registry) number. You then go to the Hazardous Substance Information System (link attached) http://hsis.ascc.gov.au/
and look up the CAS number. It will then give you a number of abreviated letters and numbers which correspond to differentlevels of risk. In this particular case, CAS # 64742-62-7 is Toxic and "may cause cancer", "Avoid exposure ..."
We are now engineering the rick of elevated temperatures being experienced by this diff by adding a thermocouple into the monitoring system and setting alarm and trip levels accordingly. Other investigations were to generate the vapour again in a lab and pass the vapour through a GC.
Thanks for the help.