Steve, I'm not in the office so I can't pull the MSDS. The bulk solvent for both regular and pro oil is denatured alcohol. In the case of the pro oil dye there is a petroleum distillate as well to extend drying time. Otherwise it wouldn't be on the MSDS. Fiebings most assuredly will not list the detailed make up of their products, what manufacturer would?
I do recall formulae change over time as jurisdictions like California outlaw certain compounds. Perhaps the Pro Oil formula has changed since the last time I had to look it up for a client? I will try to find a current MSDS for it when I'm in the office Monday. They expire every three years.
redux...
I found an ancient (1992) MSDS for spirit dye
http://www.wardrobesupplies.com/spree/p ... 1332779696
Ethanol is denatured by an addition of methanol so it cannot be consumed safely. (i.e. resold for beverages)
an old MSDS online 2008
http://www.wardrobesupplies.com/spree/p ... 1345149003
Major components : diethylene glycol monoethylene ether, ethanol, isopropanol, xylene, ethyl benzene, ethyl acetate
I am by no means an organic chemist but aside from ethanol, I think the latter are petroleum distillates. Xylene is nasty stuff.
Is that helpful in any way?