Does my IRB approval mean I have access to student data?
If a student consented to your accessing their student data, then you have access to the anonymous data they consented to give. If they did not give their consent, then you must become a designated school official. The process to become a designated school official is done through the Office of Institutional Research and you can read about it here.
What is designated school official for research purposes?
A designated school official is a university employee, who is doing research that will affect the institution. An example would be research to see if certain student attributes affect retention of the student.