Biocide: A chemical or physical agent that kills all living organisms, pathogenic and nonpathogenic.

Biologic indicator (BI): A standardized preparation of bacterial spores on or in a carrier serving to demonstrate whether sterilizing conditions have been met. The type of spore varies by type of sterilization.

Cleaning: A form of decontamination that involves a detergent or enzymatic presoak that removes foreign material (e.g., dirt or microorganisms) from any object.

Decontamination:
The use of physical or chemical means to remove, inactivate, or destroy pathogens on a surface or item to the point where they are no longer capable of transmitting infectious particles and the surface or item is rendered safe for handling, for use, or for disposal. Decontamination could comprise cleaning, disinfection, or sterilization as appropriate. Disinfection: Any process, chemical or physical, that destroys pathogens such that an item is safe to handle for its intended use.

Low Level Disinfectant (LLD):
An agent that destroys all vegetative bacteria (except tubercle bacilli), lipid viruses, some nonlipid viruses, and some fungus but not bacterial spores.

Intermediate-Level Disinfectant (ILD): An agent that destroys all vegetative bacteria, including tubercle bacilli, lipid enveloped and some nonlipid enveloped viruses, and fungus spores but not bacterial spores.

High-Level Disinfectant (HLD):
A chemical or physical agent or process that is capable of killing some bacterial spores when used in sufficient concentration, temperature, and under suitable conditions. It is therefore expected to be effective against vegetative bacteria, fungi, viruses, and other microorganisms. It does not kill high numbers of bacterial spores.

Sterilization:
The complete elimination or destruction of all forms of microbial life and is accomplished in health care facilities by either physical or chemical processes. It is recommended that any instrument or equipment classified as critical that comes in contact with the blood stream or with subdermal tissues be cleaned and sterilized between each use. Sterilization is accomplished principally by steam under pressure, by dry heat, and by chemical sterilants. The choice of the method for sterilization depends on a number of factors including the type of material that the object to be sterilized is made of, the number and type of microorganisms involved, the classification of the item, and availability of sterilization methods.