What olympic said. It would be safe for you to strike a match and smoke around a puddle of ATF, but you wouldnt do the same thing near a puddle of gas would you? The difference between the two here is volatility. The more volatile, the more risky. You could hold a match over a puddle of ATF or oil and not start a fire.....you do that with any type of volatile solvent, you will be missing your arm hairs.