Article V, section 1(3) of the Colorado Constitution reserves to the people the power to refer all or a portion of an act to the ballot for voter approval. There is an exception to this power: if an act is necessary 1) "for the immediate preservation of the public peace, health, or safety"; or 2) for appropriations to support and maintain a state department or institution. The General Assembly invokes this exception by including language, referred to as a "safety clause", at the end of a bill. Further, the General Assembly is vested with the exclusive power to determine whether the exception to the referendum power applies, and the courts will not review or call into question the General Assembly's decision.
If an act does not include a safety clause, it is subject to the power of referendum, and an individual has 90 days after the General Assembly adjourns sine die to exercise that power by submitting a petition to the Secretary of State's office. Thus, an act that does not have a safety clause must include an act-subject-to-petition clause, and the act cannot take effect until at least 90 days after the General Assembly adjourns sine die.