If you’re anything like me, you’ve probably found yourself staring at a propane tank that’s been sitting around for a while and wondered: does propane go bad? It’s a fair question—and the short answer is no, propane itself does not go bad. Unlike gasoline or diesel, propane is a non-perishable fuel that can last indefinitely when stored properly.

But here’s the catch: while the gas itself won’t spoil, the tank and components that store propane absolutely can degrade over time. Let’s break down what that means and what you should be keeping an eye on.

Propane Doesn’t Expire, But Your Tank Might

Propane is a hydrocarbon gas stored under pressure as a liquid in your tank. It’s chemically stable and doesn’t oxidize or separate over time like other fuels. That’s why it’s considered a non-perishable fuel.

That said, the container it’s stored in—especially portable 20-pound tanks used for grills—can rust, leak, or become unsafe to use if it’s not properly maintained.

Check out this clip from Homeowner Repair:

Tank Expiration Dates

Did you know your propane tank has a born-on date? Look for a stamped date on the collar of the tank (usually in MM-YY format). Most tanks are certified for 12 years from the manufacture date (in the U.S.), after which they either need to be requalified or replaced.

If your tank is past its certification, many propane refill stations won’t top it off, and for good reason. Safety first.

Does Propane Go Bad Over Time?

While the gas doesn’t go bad, here are a few things that can make a stored tank unsafe or unusable:

• Valve Corrosion or Failure: Exposure to moisture or rough handling can damage the valve, which can lead to leaks or difficulty connecting to your grill.
• Rust and Pitting: If the tank has been stored in wet or salty environments (like near the coast), rust can weaken the shell.
• Residual Smell or Odor Fade: Propane is odorless in its natural state, but an odorant (ethyl mercaptan) is added to help detect leaks. Over time, the smell can fade—especially if the tank’s been stored open or partially filled.

If your tank smells weird, has visible damage, or the valve is sticky or cracked—replace it.

How to Store Propane Properly

To keep your propane tank in great shape for the long haul:

• Store it outdoors in a well-ventilated area, upright, and away from direct sunlight. You can easily get propane tank covers that can match the decor of your outdoor setup, which we highly recommend doing.
• Keep it off wet ground to prevent rust. Use a tank base, bricks, or even a plastic milk crate.
• Never store it indoors or in a garage attached to your home.
• Close the valve tightly when not in use.
• Use a protective cap or plug on the valve if storing for winter or long periods.

Final Thoughts: Does Propane Go Bad?

No—propane doesn’t go bad, but your tank or valve can, and that’s where safety and performance issues creep in.

If your tank is past its expiration or just looking worse for wear, it might be time to recycle it and grab a new one. Better safe than sorry—especially when you’re firing up for a weekend cookout.

More Propane Grill Resources:

• Best Gas Grills Under $500
• Best Built-In Gas Grills

FAQs: Does Propane Go Bad?

Does propane go bad?

No, propane itself does not go bad. It’s a stable, non-perishable fuel that can last indefinitely if stored correctly. However, the tank it’s stored in can degrade or become unsafe over time.

What is a non-perishable fuel?

A non-perishable fuel is one that does not degrade, separate, or oxidize over time—meaning it can be stored for years without going “bad.” Propane, unlike gasoline or diesel, falls into this category.

What is oxidation?

Oxidation is a chemical reaction that occurs when a substance (like metal or fuel) reacts with oxygen. In fuels like gasoline, oxidation causes breakdown and spoilage. Propane, being a simple hydrocarbon gas, does not oxidize under normal conditions.

What does propane smell like?

Propane is naturally odorless, but manufacturers add a compound called ethyl mercaptan to give it a strong, sulfur-like or “rotten egg” smell. This helps detect leaks easily.

How do I check if my propane tank is expired?

Look at the collar or handle of the tank for a stamped date in MM-YY format. Tanks are typically valid for 12 years from that date. After that, they need to be re-qualified or replaced.

How do I check if my propane valve is damaged or expired?

Inspect the valve for cracks, rust, or stiffness when turning. If it’s hard to open, leaking, or visibly corroded, it’s time for a replacement. Always test connections with soapy water for leaks.

How should I store my propane tank when not in use?

Store it outdoors, upright, in a cool, dry, well-ventilated area, and never inside your home or garage. For added visual effect outside, get a propane tank cover that also acts as a table to your outdoor furniture setup. Protect the valve with a cap or plug and ensure it’s turned tightly off.

Happy grilling, and stay safe out there! 🔥