Does Propane Go Bad, or Should I Only Worry About the Tank?

December 15, 2023
Written by Kristy J. Norton

Propane has no shelf life or a “use by” date. That’s because propane doesn’t go bad, unlike other fuels like kerosene, diesel, or gasoline.

I get it, though. Because other fuel sources have their shelf lives, there’s a common misconception that propane can “go bad” over time. And that can make you wonder if it’s still safe to use and efficient. So, you want to know how long you can store it away. These questions keep you up at night when you’ve got a big propane tank in your backyard.

Don’t sweat it, though. I’ve always depended on this fuel for long-term powering of my grills. So stick with me, and I’ll explain why propane is your trusty, long-term fuel source. I’ll also show you how to keep it for safe storage. 

does propane go bad

Does Propane Expire? Let’s Clear the Air!

In the world of gasses, liquid propane is like the eternal optimist – it doesn’t go bad or hit an expiration date. Propane is a gas that gets compressed into a liquid form and can keep its quality for the long haul. 

It’s nothing like those high-maintenance fuels that decide to expire on you after one to two holidays away from home. You can store propane away for an extended period (or almost indefinitely) after getting it from a propane delivery service. 

Just remember the golden rule: store it properly in the right containers.

But hold up! You’ve probably seen the “expiration date” on a tank or its gauge and thought “Wait, if it doesn’t expire, why the date?” Well, that expiration date is for the tank and not the gas. As you know, the metal used in LPG cylinders expires – that is, they can rust and degrade from the outside. The propane inside? Still good to go! So it’s the gas tank that needs inspection, recertification or swapping out. 

But still, there is usually no water or oxygen in a sealed propane tank. So it doesn’t rust inwardly or damage quickly. That’s why it’ll take 10 to 12 years for a high-quality and certified tank to expire. Meanwhile, a recertified tank will take around five to 12 years before expiration. Recertification here means “requalification” of an expired (earlier certified) tank. It’s all about taking the tank out for inspection, replacing the relief valve, and embedding a stamp that shows the date of its last inspection.

Why Propane Stays Fresh Forever? (or Almost!)

First, propane is a hydrocarbon gas that doesn’t go bad because it remains chemically stable, just like you left it.

Think about it: we store propane in sealed containers. It’s like putting your moisture-free foods in an airtight container to keep ’em fresh. 

If that container stays intact and tightly sealed, your propane inside keeps its quality game strong. These are conditions not always kept in the storage of other fuel sources like gasoline, kerosene, and diesel. And that’s one of the reasons they go bad (and quicker, too). 

Male Hands Opening the LPG Cylinder Valve

What Happens if You Use Old Propane?

So, like I said before, using old propane itself is not a big deal. The storage tank is what causes the problem.

An expired propane tank hiding under your grill could spell trouble. I don’t recommend using such. You can have problems such as gas leaks and, heaven forbid, fiery situations. 

The National Park Service (NPS) drops a not-so-fun fact on us: propane tanks caused up to 3,200 residential fires between 2003 and 2007, causing up to 77 deaths and 287 injuries. So, before you fire up a grill with propane from an expired tank, think again!

Can Propane Freeze?

Yes, it can! Propane goes all frosty when the temperature drops. It reaches the freezing point at a bone-chilling -44 degrees Fahrenheit. Now, picture those freezing New York winters upstate, and you’ll get why this matters.

When it’s frigid outside, your propane starts to contract. That’s why your propane tank gauge might show lower levels. But before you go into full-blown “I’m losing propane” panic mode, it’s likely just the propane shrinking inside the tank.

The secret to avoiding cold-weather propane problems is keeping your tank from hitting empty. That is, refill your tank during wintertime once you feel there is less than one-quarter of gas left. When cold causes the gas to shrink and the fuel is too low, the pressure reduces. Then the gas may not reach your burner.

So, How Do I Store My Propane Tank?

Storing your gas tank is a bit like taking care of a pet rock – simple but essential. Here’s the scoop:

  • Find a cool, dry spot: First, find your tank a comfy home. Pick a cool, dry place where the temps stay below 120 and above -40 degrees Fahrenheit. This keeps your tank frost and rust-free. 
  • No indoor storage: Propane bottles are like summer guests; they don’t belong indoors, especially if your space resembles a sauna. Indoor storage is a big no-no because if that tank decides to spring a leak, things can go south real quickly.
  • Store outdoor: Outdoor storage is the way to go. Just find a flat, cool spot, and if you’re feeling fancy, you can even build a shed over it for some extra protection. Keep that tank upright, and a little elevation off the ground works wonders in keeping it dry and stable.

Can I Store Propane Tanks Outdoors in the Winter?

You can still store your tank out in winter by using some tricks. After all, you can’t store propane indoors. Heat is the enemy your LPG tank should absolutely avoid. To keep that tank insulated from cold and rust-free, just slap a plastic coating on it. You may also get a suitable ventilated propane gas blanket for the tank. The gas stays safe, and you stay worry-free!

You should also watch out for damp spots or moisture hangouts. They’re the rust’s best friends.

Propane Gas Cylinders Arranged on the Shelf

FAQs 

1. How Long Will Propane Last if Not Used?

Propane lasts indefinitely if stored properly. Just make sure the tank is still safe and unexpired. 

2. Is It Safe to Use a 20-year-old Propane Tank?

It’s generally not safe. Gas cylinders last for 10 to 12 years. At 20 years, the tank may need recertification. 

3. How Do You Know When Propane is Bad?

Propane itself doesn’t go bad, but check tanks for rust or damage.

Conclusion

Propane is a reliable fuel source that doesn’t go bad over time, like gasoline or kerosene. The key is to store it in proper conditions, and it’ll stay fresh indefinitely. While using old propane isn’t an issue, an expired tank can lead to trouble, including gas leaks and fires. Therefore, it’s imperative to store your propane tank outdoors in a cool, dry location, as indoor storage poses safety risks.

By Kristy J. Norton
I'm Kristy – a chef and connoisseur of all things BBQ! You can find me either in my kitchen (or someone else's) or at a big outdoor barbecue surrounded by friends and family. In both my professional and personal life I’ve picked up more than a few tips and tricks for turning out delicious food. I consider it a privilege to share it with others!
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