[MAexile]

Forget 12%! We have a room at work where the nitrogen dewars are kept that has an oxygen monitor for obvious reasons. It goes off when the Oxygen level reaches 19%, warning people to NOT GO IN!

[gridlock]

If you have done any work in the field at all, you would know that before you reached a major city with 12% atmospheric oxygen, you would be passing cities and towns full of dead people for hundreds of miles.