To enforce this subtitle, the Secretary or a representative of the Secretary at any reasonable time may: Enter and inspect any factory, warehouse, or establishment in which the Secretary believes hazardous material is manufactured, processed, packaged, or stored; and Enter and inspect any vehicle that is used to transport or hold hazardous materials in commerce. As part of any inspection under subsection (a) of this section, the Secretary may inspect any pertinent equipment, labeling, or finished or unfinished substance or toy. Before entering to make an inspection under this section, the Secretary or representative of the Secretary shall present appropriate credentials to the owner, operator, or agent in charge. During an entry and inspection under this section, the Secretary or representative of the Secretary may obtain a sample of any substance, toy, package, or labeling. When obtaining a sample under this subsection, the Secretary or representative of the Secretary shall: Pay or offer to pay for the sample; and Give the owner, operator, or agent in charge a receipt that describes the sample obtained.