From the Senate Handbook, Article III.C.4.:

"Resolutions from any senator can be considered new business if: a) the time available and the circumstances do not allow that the resolution go through the normal process of consideration by a committee; b) the resolution has been submitted in writing to the executive secretary before it is put to a vote; and, c) the issue is pertinent to the mission of the Senate. It shall be the responsibility of the chair to rule on the application of these criteria."