Does an escape mask come with its own oxygen supply?
No. Escape masks are designed to protect your respiratory system from various chemical or biological agents or lethal gases produced as a result of a fire, therefore buying you time to remove yourself from the vicinity of a disaster. They are designed to be light weight and compact enough so that you can carry them with you whenever you are within an area which you feel may be high risk. Including an oxygen supply would make the mask too bulky for it to be practical to carry with you at all times.
