Re: Is pure oxygen explosive?

An explosion is a very fast chemical reaction. Oxygen, if contained by 
itself in a non-reactive environment (say, for instance, in a glass 
container) is not explosive. However, if provided with an agent with which 
to react, ie, anything we'd call flammable, it is highly reactive. If you 
mix hydrogen and oxygen in a container and provide a source of heat, you'll 
definitely get a "bang for your buck".

Dan Berger adds:
Any mixture of fuel and oxidizer can be explosive; gunpowder is an example
(the oxidizer is saltpeter), as are fuel-air explosives which are exactly
similar to what goes on in the cylinders of your car (air is mixed with fine 
droplets of fuel, then ignited) on a much larger scale.

Even asphalt (which is a mixture of hydrocarbon tar with gravel) can explode 
if soaked in liquid oxygen.