Mich. Comp. Laws § 722.113b

Sec. 3b. (1) An individual shall not smoke in a child caring institution or child care center or on real property that is under the control of a child caring institution or child care center and upon which the child caring institution or child care center is located, including other related buildings. The operator of a child care center shall conspicuously post on the premises a notice that specifies that smoking on the premises is prohibited. (2) As used in this section and section 3c, "smoke" or "smoking" means those terms as defined in section 12601 of the public health code, 1978 PA 368, MCL 333.12601.