B100 should have no alcohol in it. If you were making it yourself it could if you dont process it completely.
Biodiesel is a very good solvent, degreaser etc. It's inherent properties will degrade natural rubber. Most people say about 6 months or so and the rubber fuel lines start weeping and need to be replaced. Newer rigs dont have this problem because they no longer use any natural rubber components in the fuel system. I have had no probs in my 96 ford.
BTW it will also eat paint if routinely spilled on it and left without cleaning it off.
