225 ILCS 710/13
Whenever the inspector receives a complaint in writing, signed by 5 or more persons employed in a mine, setting forth that the mine in which they are working is being operated contrary to law and is in any respect dangerous to the health and lives of those employed therein, the inspector shall in person examine such mine as soon as possible. The names of the persons making such complaint shall be kept secret by the inspector, unless permission to disclose them be expressly granted by the persons making the complaint.
Such complaint, shall in all cases, set forth the alleged violation of law observed, the nature of the danger existing at the mine, and the time when such violation or danger was first observed. If on inspection the inspector finds the conditions, in his or her opinion, dangerous to the health and lives of those employed therein, by reason of any violation of any of the provisions and rules of this Act, the inspector shall serve or cause to be served a notice setting forth fully the facts upon which his or her opinion is based, as provided in Section 10 of this Act.
It shall be the duty of the inspector to forward every such original complaint so received to the Office of Mines and Minerals, where it shall be indexed and filed among the official papers of the Office.
225 ILCS 710/13