An AvSax lithium battery fire mitigation bag on board a helicopter An AvSax lithium battery fire mitigation bag on board a helicopter A pilot with an AvSax lithium fire mitigation bag A pilot with an AvSax lithium fire mitigation bag Many major airlines now have AvSax  lithium battery fire containment bags on board Many major airlines now have AvSax lithium battery fire containment bags on board

Why more helicopter companies now have AvSax battery fire containment bags to deal with lithium battery fires on board

Emergency air ambulances and many other helicopter operators – many of them in critical roles worldwide – are now equipped with AvSax lithium battery fire protection bags in case of a potentially catastrophic fire on board. 

The move to protect against the danger of batteries used to power personal electronic devices comes after more than 100 airline and helicopter companies have equipped themselves with AvSax or board around 16,750 aircraft worldwide in recent times. 

The award-winning AvSax – by far the world’s best-selling lithium battery fire mitigation bag - has been deployed in action almost 20 times after electronic devices such as mobile phones or laptops overheated and on every occasion the aircraft was able to continue safely to its destination. 

In the UK more than 20 air ambulance helicopters operated by specialist aerial emergency medical services company Babcock are now protected by AvSax. 

This means that if a battery malfunctions - a process known as thermal runaway - the crew can seal the battery inside one of the specialist bags, ensuring that it stays safe even if it’s at risk of bursting into flames. The military-grade material is tough enough to withstand the force of a blast even if the device explodes, containing the heat, blast and debris. 

Thermal runaway happens when one cell in a battery overheats it can produce enough heat – up to 900°C (1652°F) – to cause adjacent cells to overheat. This can cause a lithium battery fire to flare repeatedly and they are very difficult to put out which is why AvSax battery fire containment bags are needed as they are designed to deal with this intense heat. 

A Babcock spokesman said: “Our air ambulance helicopters carry a number of battery-operated medical and aviation devices. On rare occasions lithium-ion batteries can malfunction, leading to thermal runaway and possibly even igniting.
“But our aircraft carry specialist AvSax battery fire containment bags which can cool down an overheating device and are strong enough to withstand a blast should they explode.” 

Other helicopter operators equipped with AvSax include those flying across large stretches of water or are used to inspect critical infrastructure such as electricity pylons. 

Many small airline companies worldwide, along with some of the biggest international names in the industry, already use AvSax which were devised by Environmental Defence Systems Ltd based in Huddersfield, West Yorkshire. The company won the Queen’s Award for Enterprise for their innovation – the top accolade any business can get. 

Environmental Defence Systems managing director Richard Bailey said: “The message is certainly spreading rapidly through the airline and helicopter industries that they do need some form of protection against the danger of lithium-ion battery fires on board. 

“Although rare, these incidents are happening and it’s vital they are prepared. An electrical fire in the enclosed space of an aircraft giving off toxic smoke along with flames and incredibly high temperatures could have potentially catastrophic consequences. 

“Investigators would be looking at what health and safety measures the airline operator had in place to deal with lithium batteries if such an incident was to happen.” 

It’s certainly simply not a case of throwing a burning personal electronic device out of a helicopter as the updraft could take it into the rotor blades. 

The award-winning AvSax covers the airline or helicopter company’s duty of care and responsibility to passengers as carrying one on board means the crew is: 

* Able to hold an electronic device in a bag that is so resilient it can contain the force of the device going into full thermal runaway. 

* Reduce the chance of catastrophic damage to the aircraft. 

* Reduce the risk of toxic smoke in the cabin which would be highly dangerous to both passengers and crew. 

* Means that the flight probably won’t need to be diverted. Aircraft that have deployed AvSax lithium battery fire containment bags in action have never had to divert. 

The Federal Aviation Administration in the USA and the Civil Aviation Authority in the UK have clear rules on how lithium batteries should be taken on board aircraft. Read all about them at

AvSax are the world’s best-selling fire containment bag for PEDs on aircraft and are now on more than 16,770 aircraft operated by more than 100 airline companies. They have been used 33 times to deal with emergencies since the start of 2017 and every time they have been deployed the aircraft has been able to complete its journey safely with no need to divert or make an emergency landing.

For more information go to or email