430 ILCS 35/4
The Director is authorized to conduct examinations, inspections, and investigations for the purposes of this Act through officers and employees of the Department.
For purposes of enforcement of this Act, officers or employees duly designated by the Director, upon presenting appropriate credentials and a written notice to the owner, operator, or agent in charge are authorized: to enter, at reasonable times, any factory, warehouse, or establishment in which hazardous substances are manufactured, processed, packed, or held for introduction into commerce or are held after such introduction, or to enter any vehicle being used to transport or hold such hazardous substances in commerce; to inspect, at reasonable times and within reasonable limits and in a reasonable manner, such factory, warehouse, establishment, or vehicle, and all pertinent equipment, finished and unfinished materials, and labeling therein; and to obtain samples of such materials or packages thereof, or of such labeling. A separate notice shall be given for each such inspection, but a notice shall not be required for each entry made during the period covered by the inspection. Each such inspection shall be commenced and completed with reasonable promptness.
If the officer or employee obtains any sample, prior to leaving the premises, he shall give to the owner, operator, or agent in charge a receipt describing the samples obtained. If an analysis is made of such sample, a copy of the results of such analysis shall be furnished promptly to the owner, operator, or agent in charge.
430 ILCS 35/4