Mich. Comp. Laws § 125.1513b

Sec. 13b. (1) As used in this section, "lead free" means either of the following: (a) Solder and flux containing not more than 0.2% lead. (b) Pipe and pipe fittings containing not more than 8% lead. (2) Beginning on the effective date of this section, pipes, pipe fittings, solder, or flux which are used in the installation or repair of a plumbing system in a building or structure providing water for human consumption or a public water system shall be lead free. (3) This section shall not apply to leaded joints necessary for the repair of cast iron pipes.