Yes, there are several risks that can occur from this, one of the major ones is the possibility of rupturing something internally, which might end up leading to getting an air embolism.
What is Air Embolsim?
An air embolism, or more generally gas embolism, is a pathological condition caused by gas bubbles in a vascular system. The most common context is a human body, in which case it refers to gas bubbles in the bloodstream (embolism in a medical context refers to any large moving mass or defect in the blood stream). - Wikipedia
(http://en.wikipedia.org/wiki/Air_embolism)
Self inflating rafts come with their own compressed air; that's why they are self inflating. If it was not self inflating you would have to pump air into it to inflate it. In either case, rafts can be inflated by any form of gas, it does not have to be oxygen.
The risks you could take are cutting yourself.
By breathing in and out and inflating our LUNGS
By breathing in and out and inflating our LUNGS
Self-inflating rafts have a CO2 canister that inflates the raft when it is triggered via manual or pressure release
no, its flammable.
reversible
You don't, you get it done professionally to minimize the health risks you impose on yourself.
no its a physical change
bags that self-inflate
inflating a balloon.
Only with soft tissue. Consider the puffer fish. If you have a lot of loose soft tissue then you can alter your shape considerably by inflating yourself. When we start to talk about bone, enamal, cartlage, or wood. Then no.