Notwithstanding the provisions of chapter 35 of Title 42, rules or regulations adopted by the director on or before December 31, 1966 and pursuant to authority granted to the director by law shall become effective twenty (20) days after filing those rules or regulations in the office of the secretary of state. The director shall hold a hearing on those rules and regulations, after reasonable notice, if within six (6) months of the adoption of the rules or regulations any interested person requests a hearing. At that hearing, all interested persons shall be given an opportunity to submit data, views, or arguments, orally or in writing, relative to the rules or regulations. Rules or regulations filed with the secretary of state under this section shall remain in effect notwithstanding that hearing, but following a hearing the director may file amendments to the rules or regulations as he or she deems advisable, those amendments to become effective twenty (20) days after filing. All rules and regulations of the director in effect on July 1, 1966 shall remain in full force and effect after that date unless expressly repealed by the director or by any provision of this chapter.