Each IRB Chairman and the Director, ORI has the authority to determine if a study qualifies as human subject research and the subsequent category in which it may qualify.
Requests for determinations as to whether or not a thesis/dissertation involves human subject research should be sent to the Director, ORI.
Exempt studies can be approved by the IRB Chairman or the Director, ORI.
Expedited studies can be approved by the IRB Chairman or his/her designee (IRB member).
Of course, if you are unsure whether an activity is human research or not, you should contact the Office of Research Integrity and submit an abstract for a determination on that point.