I'm only going to comment on the Classified Area part of your question, I'll leave the rest to others.

The presence of oxygen does not create a classified area. You may have gotten the blank stare because oxygen is not a flammable gas... it is an "oxidizer." Meaning that it would support or contribute to a fire in the presence of a flammable/combustible mixture (gas/vapor/dust).

[Edited to remove confusing reference see later post for more information]

That's the short answer to this part of your question, let me know if you want the long answer. [Linked Image]

[This message has been edited by safetygem (edited 01-28-2005).]