This topic came up in a lawn care group on Facebook yesterday. Some of the claims made in the comments were outrageous. Evidently, ethanol will corrode plastic fuel cells/tanks regardless if it absorbs water or not. If that was the case, how has any plastic fuel cell in all of these cars made in the past 30 years ever survived? How has any plastic whiskey bottle survived? Heavy aromatics like toluene, xylene, and ethylbenzene are more corrosive to polyethylene than ethanol, and they make up ~40% of E10 pump fuel, even more in non-ethanol fuel.
I don't doubt that ethanol can have separation issues when it absorbs too much water. That is proven to happen with science. Not everyone will see this occur depending on your climate, how well your fuel system is sealed from the elements, and how you use your equipment. When people make outrageously bogus claims though, stuff that flies in the face of even basic 5th grade science, it makes you question the credibility of other claims. Is this person actually stating what he saw happen, and conducted A-B-A testing to validate the claim, or is he just throwing flack at something because he doesn't like it for whatever reason or just repeating whatever nonsense he read somewhere. Unfortunately, with topics like this, there's more myths than facts floating around.