Found some old Zippo Lighter Fluid at home but I could not find any best before date. I think it is somewhere between 15-20 years old (new box to the right). Safe to use or should I buy new fluid?

I know that normal gasoline lasts about six months and fuel-stabilized gasoline keeps for one to three years.


According to this thread however there's nothing in lighter fluid (naphtha) that can go bad.


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  • "normal gasoline lasts about six months" Under certain conditions it's only safe for use in vehicles up till 6-months. That doesn't mean it's no longer gasoline after that. It has probably fallen apart a bit, nothing a good shake won't fix. It's still flammable. – Mast Sep 25 '20 at 8:05
  • @Mast No, a shake won't help. The problem with old gasoline is that the light fractions in the mixture evaporate over time and the fuel gradually becomes 'heavier'. This leads to poor combustion performance and excessive production of shellac and residues in the engine. Naturally, a zippo doesn't have the same tight constraints on the fuel as it has no complex mechanical system to keep in smooth working order. – J... Sep 25 '20 at 13:59
  • @J... Well, naturally, I wasn't advocating trying to start an engine with it. But for all the other crap that's now heavy in the solution, a shake helps to get it to burn somewhat decent again. At least, that's my experience. May be a matter of confirmation bias. – Mast Sep 25 '20 at 14:10
  • The other way gasoline goes "bad" is when it's had ethanol added. The ethanol attracts water so as water content increases it burns more poorly and performance declines. But that's not to say it won't burn just fine if you toss a match on it. But naptha suffers no such problem and as a stove fuel it will work just fine no matter how old. – Carey Gregory Sep 25 '20 at 15:42

Vehicle fuels have to do more than just burn. They have to ignite as expected, not clog fuel filters and not bring too much water with them; they may also have to lubricate. This means old vehicle fuels might run rough or have trouble starting. Old vehicle fuel can still be brunt in unfussy engines, at least if mixed with fresh in small quantities. New car engines can be very fussy though.

You don't say what you're using the Zippo fuel for, but for the vast majority of cases it shouldn't matter - Zippos and even stoves that run on this sort of fuel are much simpler than engines. The worst that's likely to happen is a slightly smaller flame, if lighter fractions have evaporated more than heavier ones, and that's unlikely if the container was tightly closed.

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    I'd perhaps not use it on a stove where flames sputtering a bit is potentially catastrophic. Like inside a small tent. – Stian Yttervik Sep 25 '20 at 13:08
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    @StianYttervik I wouldn't use my petrol stove in a small tent at all, and would be very cautious with my alcohol stove. Instead I'd sit/squat in the entrance (which would be the downwind end) with the stove outside. – Chris H Sep 25 '20 at 13:22
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    Amen to that, my point was; don't use mystery fuel without considering the error modes. – Stian Yttervik Sep 25 '20 at 13:45

If you are worried about putting it in a lighter or something, spurt a bit out in a safe container and light it up, see if it burns to your satisfaction, if it doesn’t, pitch it. It costs $4.50/12 oz on amazon, so if you are worried about it fouling up anything you value, again, pitch it or put 50 cents on each and have a yard sale.

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