(1) Except for a rule processed under section 48, a rule becomes effective on the date fixed in the rule, which must not be earlier than 7 days after the date of promulgation, or, if a date is not fixed in the rule, 7 days after the date of promulgation.

    (2) Except for a rule processed under section 48, an agency may withdraw a promulgated rule that has not become effective by filing a written request stating reasons for withdrawal to the secretary of state on or before the last day for filing rules for the interim period in which the rules were first filed, or by filing a written request for withdrawal to the secretary of state and the office, within a reasonable time, as determined by the office, after the last day for filing and before publication of the rule in the next supplement to the code. In any other circumstances, an agency may abrogate its rule only by rescission. If an agency has withdrawn a promulgated rule, it shall give notice, stating reasons, to the committee that the rule has been withdrawn.

    (3) Sections 45 and 45a apply to rules for which a public hearing has not been held by April 1, 2000.