Combustible "air" dusters.

Someone mentioned that some air dusters are combustible, so I got one from Poundland to try out. Normally if it was an actual air duster with compressed air in it, it wouldn't tend to be in liquid form, but this one has a modest amount of liquid in it.
It's very combustible. In fact I think it may be propane or butane, but with no odour added like in lighter fuel.

As a final test of combustibility I emptied a gas lighter and refilled it by inverting the air duster can into its refill valve. It burns just like butane would.

I guess that in the same way that an aerosol air freshener uses butane as a propellant, it's no real hazard if the gas is being sprayed in moderation. But I wouldn't recommend its use on anything "sparky" like a motor or open contacts.