Bringing it back to facts:
304 Stainless, 6061 Aluminum, and their oxide surface layers are safe for use in E85.
LINK to journal publication
Dupont has a thorough list of reactivities to various solvents:
LINK to charts
The EPA should be an expert in these things... since they are advocating its usage. Here's a list of publications describing the storage and standards surrounding Ethanol-Gasoline blends.
LINK to homepage
The Dept of Energy has a very thorough overview of Ethanol and the infrastructure required for gas stations. Aluminum (assuming 6061 is exempt) and brass must be plated before use.
LINK to PDF
** Appendix B (page 39) of this paper by the Renewable Fuels Foundation shows the list of materials that were soaked in ethanol for 30 days at 110 degF and showed NO decrease in mass when compared to identical gasoline testing.
LINK to PDF
Metals:
Aluminum alloy
Magnesium alloy
Copper
Zinc
Carbon steel
Cartridge brass
Aluminum bronze
Stainless steel
Aluminum alloy (cast)
Iron (cast)
Zinc alloy (cast)
Terne plate
Plastics:
Nitrile
Viton®
Neoprene® (Chloroprene)
Epichlorohydrin
-Homopolymer
-Copolymer
Nylon 6 6
Delrin® (Acetyl polymer)
Teflon®
Polyethylene (high density)
Nitrophyl® (Nitrile rubber)
Fluoroelastomers