Abstract: The present invention provides a non-intrusive technique for determining whether people and items have been properly cleaned before entering a controlled area. In one embodiment, soap is provided in washrooms, restrooms, sculleries, or other types of facilities for cleaning people and items entering a controlled area. A sensor detects the presence of metallic or other constituents of the soap left behind on the people and items after proper cleaning. The sensor's output is read to determine whether the people and items have been recently cleaned. Specific people and items can be identified by detecting a signal from a device, such as a radio frequency identification tag, attached to people and items entering a controlled area. For people, the tag can be incorporated into a name badge or into work clothing.