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.
Well, considering that many early spacecraft and space stations were running oxygen rich atmospheres, it would probably mean the end of anyone involved in a rather spectacular fireball.
I’d kind of hope everyone would know better than that after the disastrous Apollo I fire.