How AvSax battery fire containment bags solve the problem of electronic devices powered by lithium-ion batteries going into thermal runaway on aircraft

Passengers take hundreds of small electronic devices including mobile phones, ipads, tablets, e-cigarettes and laptops on board planes and helicopters every day ... but very few are aware there is always the possibility that the rechargable lithium-ion batteries inside them could overheat and catch fire.

When this happens it's called thermal runaway. If one cell in a battery overheats it can produce enough heat – up to 900°C (1652°F) – to cause adjacent cells to overheat too. If this happens in the confined space of an aircraft if can have potentially catastrophic consequences but fireproof AvSax lithium battery fire containment bags - also known as burn bags, firebags or thermal containment bags - can significantly reduce that danger in seconds.

Simply pour in at least 2 litres of water and pop the overheating or burning device into the AvSax fire containment bag which some airlines know as burn bags. The bag's polymer gel inside expands to totally surround the device, instantly cooling it down to minimise the risk by adding further water. If it should still vent, the polymer is designed to absorb the force and it can hold in the force of an exploding lithium-ion battery.

Our blog is probably the most comprehensive one in the world on the subject of thermal runaway incidents on passenger aircraft.

Why AvSax are needed

Watch the videos to see why AvSax fireproof fire mitigation bags are so important in today's technology-focused world and find out how they work.


AvSax fire containment bags are innovative heatproof bags specially designed for emergencies.

Minimise the danger

Minimise the risk on-board aircraft.

Thoroughly Tested

Stringent tests have proved their effectiveness.

Just add water

AvSax contains a gelling polymer that forms a tight seal when water is added.

500+ Batteries on board!

A plane carrying just 100 passengers could have hundreds of batteries on board.

An aircraft essential

AvSax should be carried on all aircraft.


Compact and lightweight for use onboard General Aviation, Commercial, and Military aircraft.


AvSax fireproof fire mitigation bags can be deployed quickly and efficiently to contain devices of all shapes and sizes that may go into thermal runaway. The kind of small electronic devices that easily slip into AvSax fireproof fire containment bags include mobile phones, ipads, tablets, e-cigarettes and laptops.

AvSax fire containment bags are designed to deal with fires in electronic devices caused by lithium ion batteries on board aircraft
AvSax fire containment bags are vacuum-packed so are space-saving to stow on aircraft but can quickly be deployed to deal with lithium battery fires
AvSax fire containment bags meet Civil Aviation Authority regulations
AvSax smoke mitigation bags are quick and easy to deploy in an emergency
AvSax fire containment bags are designed to be used both on the flight deck and in the passenger cabin
AvSax fire containment bags can contain a range of different sized electronic devices.

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