[Silound]

For the record, the *new* Zippo fuel is odorless and flavorless when burned, this I have personally verified for my pipe. The old version is no longer produced, but Zippo only made a halfhearted effort to pull the existing stock back.

The safest option is ethanol, which simply converts to carbon dioxide and water vapor during combustion. You're going to run into a handful of problems trying to use an alternative fuel though. Most fuels are designed to have a relatively low vapor point as to be easily ignited, but are mixed with other compounds to improve the ability to keep when not in a sealed container. Ethanol would evaporate too fat to have any viable keeping power.