How old do you have to be to buy zippo lighters in Hawaii?

You can be any age to buy an empty Zippo. They may question you if you look really young. The best place to get one would be a corner store or some gas station, they usually don't care about age. The thing is, you can be any age to buy an empty lighter but you have to be 18 to buy the fuel for them. I live in Fl and I'm 17 and bought one. Not the fuel though, some I.D. you for fuel.