All research involving human subjects must be submitted for IRB approval. It is the responsibility of the IRB to determine if the proposal requires full committee review, expedited review, or is exempt from review.

In general terms, the criteria are as follows:

Full review is required for all human subject research involving more than minimal risk to subjects/participants and for research involving vulnerable populations (e.g. children, mentally or physically handicapped people, prisoners). Research in which the identification of the subjects and/or their responses would reasonably place them at risk of criminal or civil liability or be damaging to the subjects' financial standing, employability, insurability, reputation, or be stigmatizing must be submitted for review. 
See Forms : Request for Review (Non-Exempt)

Research projects in which the likelihood of harm or discomfort is not greater than that encountered in daily life or during the performance of a routine physical or psychological test is subject to expedited review. The project does not involve sensitive topics or confidential information that could place a participant at risk if disclosed. 
See Forms : Request for Review (Non-Exempt)

Most research involving the use of educational tests (cognitive, diagnostic, aptitude, achievement), survey procedures, interview procedures or observation of public behavior in which the identity of the subject cannot be established is exempt from review. This includes collecting or studying existing data, records or specimens, if these sources are publicly available or if the information is recorded in a way that the subjects cannot be identified. Please note that the exemption category pertaining to survey or interview procedures or observations of public behavior, does not apply to research involving children, except for research involving public behavior when the Investigator does not participate in the activities being observed.

The IRB chair determines whether a research project is exempt from further review. Thus, even if an investigator expects that a project will be exempt, they must submit it for review. 
See Forms : Request for Exemption

For help with determining if IRB approval is required, please refer to the decision tree:

Decision Tree 

Survey Monkey Decision Tree created by Alison Donta, director of Institutional Research at Mount Holyoke College