Mich. Comp. Laws § 125.2503

Sec. 3. (1) Beginning 1 year after the effective date of this act, a person shall not sell in this state a heating cable that has not been approved by the state construction code commission pursuant to section 21 of the state construction code act of 1972, Act No. 230 of the Public Acts of 1972, being section 125.1521 of the Michigan Compiled Laws. (2) The department shall compile and revise as necessary a list of heating cables that have been approved by the state construction code commission and that may be sold in this state.