Lighters are one of the things that is completely forbidden to carry in cabin during a commercial flight, but my guesses are the risk is more related to fire itself rather than exploding. You can still carry them in your checked bags, so I don't think there is a risk of explosion under normal circumstances at least. Airplane security takes fire hazards as serious as they are.

Also, you have to take into account that the plane is pressurized to stay between 0.8 to 0.7 atm, which is the pressure you can find on a ~1.500 m high mountain (might also depend on the weather). You can find many people living at that level all over the world, and they use lighters normally (this makes sense, the inside of the cabin must be habitable and comfortable for people).

Also, let's say you have a half broken lighter and the lower pressure inside the cabin makes it break: I also doubt it would "explode", the liquified gas would simply escape the container and become air. It's still flammable, of course, but without a spark it doesn't mean much, and it'll probably disperse fairly quickly anyway.

#science #englishmyles