What materials are best to use with 200 proof ethanol?

The best materials to use with 200 proof ethanol would be anything that has excellent chemical compatibility and/or is a non-reactive material. Non-reactive materials are materials used to store or hold chemicals, food, and fuels without risk of a dangerous or adverse chemical reaction.

Some examples of materials that are non-reactive and/or have excellent chemical compatibility are:

• Acetal (excellent chemical compatibility)
• Glass (non-reactive and excellent chemical compatibility) 
• Some metals, including:
• Copper (non-reactive and excellent chemical compatibility) 
• Stainless steel (non-reactive)
• Nylon (excellent chemical compatibility)
• Some plastics (including certain Nalgene® plastics), including:
• HDPE or high-density polyethylene (non-reactive and excellent chemical compatibility)
• LDPE or low-density polyethylene plastic resin (excellent chemical compatibility)
• PP or polypropylene (excellent chemical compatibility)
• PMP or polymethylpentene (excellent chemical compatibility)
• Teflon® or PTFE (polytetrafluoroethylene) (non-reactive and excellent chemical compatibility)
• Viton® (excellent chemical compatibility)

Materials that are mostly compatible but can sustain damage after prolonged exposure include:

• Aluminum
• Carbon steel 
• PVC pipe or tubing

Materials that are not recommended but are commonly inquired about include: 

• Brass (some brass alloys may contain lead which can leach into the ethanol after prolonged contact)