DEFINITIONS:Contamination: The presence of microorganisms on an item or surface.Cleaning: The process of removing all foreign material (i.e., dirt, body fluids, lubricants) from objects by using water and detergents or soaps and washing or scrubbing the object.Critical device: An item that enters sterile tissue or the vascular system (e.g. intravenous catheters, needles for injections, scalpels,...