Cleaning is the physical removal of foreign material and organic material. Cleaning physically removes rather than kills microorganisms. It may be accomplished with water, detergents, and mechanical action, and is often a necessary first step prior to disinfection or sterilizing a surface.
Surfaces (office areas, lobby countertops, keyboards, floors, door handles) and non-critical devices (stethoscopes, otoscope handles blood pressure cuffs), do not normally come in contact with patients/clients or would only ever touch intact skin. Examples include office areas, lobby countertops, keyboards, floors, door handles, chairs, etc. Non-critical devices require low or intermediate-level disinfection. Disinfection involves the destruction of disease-producing microorganisms, including bacteria, viruses, and fungi.
Semi-critical devices are devices that may break the skin during use but are not intended to penetrate skin or contact normally sterile tissue. Examples include nail clippers, nippers, tweezers, nail files, foot files, etc. Semi-critical devices typically require high-level disinfection for appropriate reprocessing. High-level disinfection eliminates vegetative bacteria, enveloped and non-enveloped viruses, fungi, and mycobacteria.
Critical devices are those that penetrate the skin or mucous membranes to enter normally sterile tissue or have direct contact with the bloodstream. Examples include foot care equipment, surgical tools, eye equipment, etc. Critical devices require sterilization, to prevent disease transmission by microbial contamination. Sterilization results in the destruction of all forms of microbial life including bacteria, viruses, spores, and fungi.