Figures have proved just how rapidly the number of fires on board aircraft caused by lithium-ion batteries is growing.

In 2017 there were 46 recorded lithium-ion thermal runaways in passengers’ carry-on luggage and backpacks or while devices were in use, either on board commercial airliners or in boarding lounges at airports. Most were on board aircraft and that equates to around one every eight days.

In 2016 there were 31 incidents – just about double the 2015 tally of 16. In 2014 there were nine and in 2013, eight. Sixteen thermal incidents had been recorded this year by the end of April.

The figures recorded by the Federal Aviation Administration’s Office of Security and Hazardous Materials Safety were published by Aviationweek.com.

The website quoted Mark Millam, vice president-technical at the Flight Safety Foundation, as saying: “We never considered lithium batteries an aviation safety threat but here you have a small battery that holds so much energy in comparison to its predecessors like NiCad and NiMH batteries that now if something goes wrong you can have explosive events.

“And they’re so prevalent in all kinds of applications - like cellular telephones - that statistically, and based on what we know about their stability in certain situations, they can be considered a threat.”

Aviation-related thermal runaway incidents are increasing year on year because as the popularity of digital devices grow, from “smart” mobile phones, tablets, laptop computers and related chargers to wireless headsets, electronic cigarettes (e-cigs), and even heated socks — all are powered by lithium-ion batteries.

Just about any airline flight today contains hundreds of li-ion batteries active in passengers’ electronics or in chargers, either in carry-on baggage or plugged into the USB ports in seat rows.

For more on this go to http://aviationweek.com/business-aviation/lithium-battery-hazards-know-how-respond-when-heat

*  More than 50 airline companies across the world – including some of the biggest and best-known - now carry AvSax fire containment bags to deal with fires in personal electronic devices caused by lithium-ion batteries that power them.

The bag – which won the Queen’s Award for Enterprise this year - has been used 27 times to deal with emergencies since the start of 2017.