Concentrated oxygen is NOT natural. Tell me where to find the "Oxygen Trees" from which they are picked?
It is a drug, and like all drugs, has potential issues, although I'm not specifically talking against it here.
There are situations in which high concentration Oxygen can be lethal, or cause blindness, although neither situation would apply to this activity.
However, when people talk about drugs as "natural", it always make me cautious, and you should be too.
