How Long Can Gas Sit In Your Grill Tank Before It Goes Bad?

You're preparing for your first backyard cookout of the season, dusting off your gas grill to whip up some burgers for your friends and family, but as you pull off the cover and get everything set up, a question floats through your mind: When was the last time you actually used the grill? Last year? The year before? It's natural to wonder if it's actually safe to ignite — after all, gasoline is no longer usable after a few months — but before you panic and decide to send someone out for a new tank, take a breather. Propane doesn't degrade like gasoline does, so as long as your tank is in good condition, you should be able to use it for years to come.

With that being said, however, the date on your propane tank does actually mean something. While the gas itself doesn't break down or lose its flammability, the metal tank could become damaged over time. This isn't anything to worry about if you bought your tank a few months or even a couple years prior, but your propane tank is technically "bad" 12 years after the date of manufacture. This date can be found stamped on the top of the tank near the valve. While 12 years is a massive window to work with, this warning shouldn't be forgotten or disregarded — a 12 or more year old tank is actually illegal to refill under federal law, and the damage that comes with age could result in dangerous consequences if you still decide to go ahead with using it.

Even if your propane tank is within the 12-year window, it should still be inspected for signs of damage each time you decide to use it. If it's rusty, dented, or has damage to the valve or collar, it's a better idea to exchange it or buy a new one. Propane isn't something you want to play fast and loose with — a bad tank could result in leaks, burn injuries, or even explosions in severe cases. Avoiding the common mistake of using an old tank is one of the best ways to reduce your chances of harm, and considering the fact that a new tank is only around $22 with an exchange, it's not worth the risk.

If you're coming up on the 12 year mark but your tank still looks like it's in good shape, you have two options: you can either exchange your old tank for a new one, often earning a major discount on your purchase, or get your existing tank re-certified. Re-certification extends the "expiration" date of your tank for five more years. You do have to pay for this service, and it requires calling out a professional from the Department of Transportation for an inspection. We'll be honest — this is a hassle. Most gas grills only use a 20 gallon tank, so it's much simpler to head to a convenience store, gas station, or hardware store to swap out the old tank for a new one.