CargoRat2,
I'm glad you brought up the old subject about the lighters. Had completely forgotten about it.
I was in Morocco recently and had to buy a lighter. I put it in my shirt pocket and a few minutes later a felt a cool sensation against my chest.
It turned out that the lighter -- maybe I placed it my pocket upside down -- I don't know, leaked butane. Of course, when a small amount of butane comes in contact with oxygen it evaporates and creates a combustible gas. Luckily I was not smoking at the time or it could have been a little flamable.
I, for one, can not imagine transporting these type of dangerous goods anywhere. I don't want to scare anyone, but my company deals in tank container shipments in all IMO classes. We ship propane, similar to butane, but if the pressure from the liquid turning to gas is too much, they have a safety valve, which stored on the deck of a ship, will just vent into the air.
An airplane is different. Just imagine if this leak is in the belly of an aircraft with no place to get out. Methane gas (house gas) has an ignition point of between 8 and 13% of the total atmosphere. I think the same is true in its gaseous state of propane and butane.
As I said, I don't want to scare anyone, but this is not a picnick. Make sure you have ventilation (if possible) if you are carrying these dangerous goods. Again, I think these lighter are of the cheapest unknown Asian origin, probably China, since in Europe they don't have to mark the country of origin.