It was purportedly (and probably in actuality) intended as a survival aid to be used after landings and before recovery in the Siberian wilderness, although allegedly was intended as a defensive weapon against in-space attacks by the US space program.
Gunpowder does actually require oxygen to burn, it just happens to bring its own oxygen with it.
That’s what I assumed, but why ass-ume when I live in the information age 😁