[kingu]

While I love BIC lighters and Zippos, if you're talking about a bag which may or may not be touched for years at a time, I use a permanent match. The fuel is sealed in the container, and I've come across ones which had been sitting there for ten years with little issue:

That said, just stick an old zippo, a SEALED container of flints and a fuel bottle in your bag if you've got the room. Easier to use, gives you far more flame, and you've got fuel to use to ignite even wet wood, and easily lasts decades in storage.

[Comment Not Approved]

Started a grass fire with a permanent match once. Overfilled it and the flaming lighter fluid spilled onto the grass.

Had a lively time stamping it out. Never used it again.