Stoves and water

Isobutane-propane blend

Also called iso-butane, canister fuel, iso-pro

What is an isobutane-propane blend?

Isobutane-propane is the fuel blend inside standard threaded backpacking canisters, usually around 80 percent isobutane and 20 percent propane. Propane provides cold-weather pressure, isobutane provides most of the burn time.

Typical blend: About 80% isobutane, 20% propane
Thread: Lindal valve, cross-brand compatible
Cold limit: Struggles below about 20 F

What each gas is doing

The two gases do different jobs. Propane vaporises at a much lower temperature, so it keeps pressure up when it's cold, but it needs a heavy pressure vessel on its own, which is why the green camping bottles are so hefty. Isobutane is easier to contain in a light canister and carries most of the energy. Blending them gets a light canister that still works in the cold.

Why the blend changes as you burn it

There's a wrinkle: the blend doesn't burn evenly. Propane vaporises preferentially, so the first part of a canister is propane-rich and the last part is mostly isobutane. That's part of why a canister loses performance as it empties, on top of the falling pressure, and it's why the last third of a canister is the least useful third in the cold.

Why the threads are standard

The good news is standardisation. The Lindal valve thread used on these canisters is common across brands, so a Jetboil canister fits an MSR stove and vice versa. Buy whatever's stocked at the trailhead town and don't worry about matching the brand on your burner.

What this means when you're choosing

The blend ratio if it is printed, since it varies between brands
A canister that has not been part-used, for a cold trip
Whether the threads are the standard Lindal valve, which they nearly always are

The common mistake

Saving part-used canisters for the cold trip

Propane boils off first, so a half-used canister is disproportionately isobutane and performs worse in cold than a fresh one. Use the part-used ones in summer and take a full canister when the temperature matters.

Common questions

Are fuel canister brands interchangeable?

Yes. They share the Lindal valve thread, so any threaded canister fits any threaded stove. The blend ratios differ slightly between brands and it makes little practical difference.

Can I fly with fuel canisters?

No, they're prohibited in both checked and carry-on baggage. Plan to buy fuel at your destination, which is why outfitters near trailheads always stock it.

Where this comes up

Guides on Tom's Hiking where isobutane-propane blend changes which product is right for you.

More in stoves and water

Canister stove

A canister stove screws directly onto a sealed cartridge of pressurised isobutane-propane. It lights instantly, simmers well and needs no priming, which is why it's the default backpacking stove almost everywhere fuel canisters are sold.

Integrated stove system

An integrated stove system pairs a burner with a matched pot that locks on, usually with a heat exchanger ring on the base. It boils water faster and uses less fuel than a separate stove and pot, at the cost of versatility.

Regulated valve

A regulated valve holds a stove's fuel pressure steady as the canister empties or cools. Without one, output drops off through the canister's life and falls sharply in the cold; with one, the flame stays consistent much further down.

Hollow fiber filter

A hollow fiber filter passes water through a bundle of tiny straw-like tubes whose walls are perforated with pores around 0.1 to 0.2 microns. It's the technology in almost every modern backpacking filter, and a single freeze can destroy it invisibly.

Micron rating

A micron rating states the largest particle a filter lets through, in microns. Backpacking filters are typically rated 0.1 or 0.2 microns, which stops bacteria and protozoa. Viruses are around 0.02 microns and pass straight through.

Flow rate

Flow rate is how fast a filter delivers clean water, usually quoted in liters per minute. The advertised figure is measured on a brand-new filter with clean water, and real flow drops as the element clogs with sediment.

Backflushing

Backflushing pushes clean water backwards through a filter to dislodge the sediment clogging its pores. It's routine maintenance on a hollow fiber filter, and it's the difference between one that lasts a season and one that lasts years.

Purifier vs filter

A filter physically strains out bacteria and protozoa. A purifier also deals with viruses, which are too small to strain, using chemistry, UV light or a much finer element. Most backcountry hiking needs a filter; international travel often needs a purifier.

Soft flask

A soft flask is a collapsible bottle, usually 250 to 750 ml, carried in the front pockets of a hydration vest. It shrinks as you drink so it doesn't slosh, and you can see exactly how much water you have left.

Hydration bladder

A hydration bladder is a flat water reservoir carried inside a pack with a drinking hose routed over the shoulder. It holds 1.5 to 3 liters, packs flat against your back and lets you drink without stopping or taking the pack off.

Bite valve

A bite valve is the silicone mouthpiece on the end of a hydration reservoir's drink tube. It stays shut until your teeth compress a slit in it, then self-seals when you let go, so water only flows while you are drinking.

Quick disconnect

A quick disconnect is the two-part coupling in a hydration hose that lets you unclip the tube from the reservoir without threading it back through your pack. Both halves usually self-seal, so you can pull the bag out to refill and neither end drips.

Hard-anodized aluminum

Hard-anodized aluminum is aluminum whose surface has been grown into a thick, very hard oxide layer by an electrochemical bath. In cookware it gives a pot that spreads heat far more evenly than titanium and resists scratching far better than bare aluminum.

Last reviewed August 13, 2026. Back to the glossary

Isobutane-propane blend

What is an isobutane-propane blend?