Found an old tank? Check these four things

• Smell and sound. If you smell gas or hear hissing, stay away, keep flames and sparks away, and call your propane supplier or emergency services from a safe distance.
• Condition. PHMSA says not to fill a cylinder with excessive rust, corrosion or pitting (especially near the bottom), dents, bulges, cuts or cracks, a missing or damaged footring, collar or valve cover, or a leaking or defective valve.
• Date. Find the manufacture date stamped on the cylinder, typically on the collar around the valve. A 10-year-old tank is usually still inside its first 12-year window.
• Requalification stamp. If the cylinder is older than 12 years, look for a requalification date stamp or sticker, and read the letter after it (see below).

How to read the stamp

A requalification marking shows who tested the cylinder, the month and year, and a letter for the method. For example, 0422 E reads as April 2022, visual inspection.

If the date is past due

PHMSA states that cylinders overdue for requalification must not be refilled. Your options are to have a DOT-approved requalifier test it, exchange it for another cylinder, or replace it. A propane dealer can tell you which makes sense.

What about the propane inside?

Propane suppliers say the fuel does not degrade over time in a sound cylinder. If the cylinder is in date and in good condition, the gas inside is not a concern. If you are unsure, ask a propane supplier to inspect it before you connect it to an appliance.

Where to keep it

Local fire codes restrict storing propane cylinders inside homes and attached garages. Ask your fire department or propane supplier what applies in your area before you put a tank away.

Frequently Asked Questions

Does propane go bad?

No. Propane suppliers state that the fuel itself does not degrade or expire in storage. The cylinder is what has a date: it must be requalified within 12 years of manufacture, then again on a schedule set by the inspection method.

Can I use a 10-year-old propane tank?

Possibly. Under federal guidance a new cylinder is good for 12 years from its manufacture date, so a 10-year-old cylinder is usually still within its first window. It also has to be in good condition. Check the date stamp, then look for rust, dents, a damaged collar or footring, and a leaking valve. If you are unsure, have a propane dealer inspect it.

Can an expired propane tank be refilled?

No. PHMSA, the U.S. Department of Transportation agency that regulates cylinders, states that cylinders overdue for requalification must not be refilled. A propane dealer can tell you whether it can be requalified or should be replaced.

What do the letters after the date mean?

They show how the cylinder was last requalified. No letter means a volumetric expansion test, good for 12 years. An S means a proof pressure test, good for 10 years. An E means a visual inspection, good for 5 years.

Do unused propane tanks expire?

The date on the cylinder counts from manufacture or the last requalification, whether or not the tank was ever used. The propane inside does not go bad, but the cylinder still has to be requalified to be refilled.

What should I do with a tank I do not want?

Do not put it in the trash. The Propane Education & Research Council says to take unserviceable tanks to a licensed propane company, and smaller tanks to a propane supplier or your local household hazardous waste site.

Sources

PHMSA: Is Your Cylinder Safe to Fill? (March 2023) · PHMSA: Requalification Guidance for Propane Cylinders · Propane Education & Research Council: Tank Disposal and Recycling · Ferrellgas: Propane Tank Recertification · Suburban Propane: How Long Do Propane Tanks Last?

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