We use mineral oil in a temperature-controlled bath at work. The bath is used to maintain a constant temperature for standard resistors.
We use mineral oil to detect neutrinos.
When I was a little kid I had problems with constipation, and I was prescribed a nightly dose of mineral oil and some soft of fiber (not Metamucil … maybe wheat germ?)
I developed a bit of a taste for it. I recall a few years ago when I was erm…blocked due to medication, and I was happy to down some more.
It’s a different petroleum fraction than gasoline. I would guess that the lack of the more volatile hydrocarbons has something to do with the reason that the stuff can be tolerated. The longer chain hydrocarbons in the mineral oil just remain inert and pass on through (the laxative action appears to be a physical effect, not a chemical one - basically, it lubricates your intestinal membranes and impedes water absorption). BTW, crude oil isn’t THAT toxic - quacks sold it as a patent medicine at one time, sometimes as a liniment, but in some cases to be taken internally. Some poor jamoke already has tuberculosis or cancer, and he’s “treating” it with a big spoonful of petroleum. Unless the patient was suffering from constipation, it did squat for their condition, but generally didn’t poison them.
What Yabob says, mineral oil contains longer chains and the parafin waxy fractions.
Gasoline is the refined shorter chain hydrocarbons that can get through membranes etc
A typical gasoline MSDS sheet is here in case anyone was thinking of lubing up their digestive system with a pint of super unleaded. The additions of MTBE (or ETBE now) does not help.
http://www.albina.com/Fuel/ChevronRUGasMSDS.htm
Crude oil on the other hand is a mixture of short and long chain hydrocarbons, the ratio pretty much defines the grade of crude. Gasoline is both distilled off and cracked off of crude. If you were to take a spoonful of heavy crude I suspect not much would happen. If you were to take a pint of the lighter grades and condensates it would be the equivelent of drinking diesel/jet fuel. See here for an example of the MSDS sheet.
http://www.brownoil.com/msdsdiesel.htm
personally I will stick with the ex lax or the Yerba Mate
Before you buy a special oil for cutting boards/knife handles/butcher block , check the ingredients on the label. I know that Chicago Cutlery did (does?) sell their own oil. But the ingredients listed were mineral oil and vitamin E, the same as drugstore mineral oil. And the drugstore product is a lot cheaper.
I’ve had a different experience with mineral oil.
Whilst in the military and we were training with semtex, we were told NOT to poke at our eyes or mouth (not that it ever occurred to us) after we’ve handled the plastic explosives because of the mineral oil content. Hmm… Judging by all the contents on this thread, I’m guessing our instructor was somewhat misinformed… I’m sure he had a point, but it wasn’t because of the mineral oil but some other ingredient that might have aggravated our eyes etc.
Mineral oil is an eye irritant. I’ve also been told (though I can’t cite a source here) that relatively pure mineral oil in the eye can be hard to wash out. Apparently it forms a oily layer that has to be more or less scraped off in multiple passes.
scraped off?! Yeesh! But it’s nothing more serious than that?
I’ve gotten it in my eyes before. (I have a bad habit of rubbing them and when you’ve got mineral oil on your hands, it’s not so great of an idea.)
My eye felt gunky for a while, but it didn’t burn or sting. It was akin to the feeling that you get when you know something’s in your eye but you can’t find it-- not really a scratchy feeling; it was more like a sort of “swollen” feeling.
I didn’t go to the doctor for it. It blinked itself out by the end of the day. A good cry probably would have helped, but I was having a nice day and no opprotunity presented itself.
But, that was just residue. It wasn’t a glob of mineral oil. I imagine that would present a problem.
Some naughty-assed remark, kid. 
:dubious: 
I use baby oil, which is mineral oil with a litle fragrance added, to remove my mascara. I’ve been using it every night for 30 years. A little oil sometimes gets inside the eyes but I’ve never had a problem. I also use baby oil as a moisturizer; it does a great job, better than some of $50 cremes I’ve tried.