Sterilization is defined as a process by which an article, sur-face, or medium is freed of all living microorganisms either in the vegetative or in the spore state.
Definition of Frequently Used Terms
Sterilization is defined as a process by which an article,
sur-face, or medium is freed of all living microorganisms either in the
vegetative or in the spore state. Any material that has been subjected to this process
is said to be sterile. These terms should be used only in the absolute sense.
An object cannot be slightly sterile or almost sterile; it is either sterile or
not sterile. Although most sterilization is performed with a physical agent,
such as heat, a few chemicals called sterilants can be classified as
sterilizing agents because of their ability to destroy spores.
A germicide, also
called a microbicide, is any
chemical agent that kills pathogenic microorganisms. A germicide can be used on
inanimate (nonliving) materials or on living tissue, but it ordinarily cannot
kill resistant microbial cells. Any physical or chemical agent that kills
“germs” is said to have germicidal properties.
Disinfection refers to the use of a chemical agent
thatdestroys or removes all pathogenic organisms or organisms capable of giving
rise to infection. This process destroys vegeta-tive pathogens but not
bacterial endospores. It is important to note that disinfectants are normally
used only on inanimate objects because they can be toxic to human and other
animal tissue, when used in higher concentrations. Disinfection pro-cesses also
remove the harmful products of microorganisms (toxins) from materials. Examples
of disinfection include (a) applying
a solution of 5% bleach to examining table, (b) boil-ing food utensils used by a sick person, and (c) immersing ther-mometers in an
isopropyl alcohol solution between use.
In modern usage, sepsis is defined as the growth of
micro-organisms in the body or the presence of microbial toxins in blood and
other tissues. The term asepsis refers to any practice that
prevents the entry of infectious agents into sterile tissues and thus prevents
Chemical agents called antiseptics
are applied directly to the exposed body surfaces (e.g., skin and mucous
membranes), wounds, and surgical incisions to destroy or inhibit vegetative
pathogens. Examples of antisepsis include (a)
preparing the skin before surgical incisions with iodine compounds, (b) swabbing an open root canal with
hydrogen peroxide, and (c) ordinary
hand washing with a germicidal soap.
Sanitization is any cleansing technique that
mechanicallyremoves microorganisms (along with food debris) to reduce the level
of contaminants. A sanitizer is a compound (e.g., soap or detergent) that is used
to perform this task. Cooking utensils, dishes, bottles, cans, and used
clothing that have been washed and dried may not be completely free of
microbes, but they are considered safe for normal use. Air sanitization with
ultraviolet lamps reduces airborne microbes in hospital rooms, veterinary
clinics, and laboratory installations.
It is often necessary to reduce the numbers of microbes on the
human skin through degerming procedures. This process usually involves scrubbing
the skin or immersing it in chemi-cals, or both. It also emulsifies oils that
lie on the outer cutane-ous layer and mechanically removes potential pathogens
from the outer layers of the skin. Examples of degerming procedures are (a) surgical hand scrub, (b) application of alcohol wipes to the
skin, and (c) cleansing of a wound
with germicidal soap and water. The concepts of antisepsis and degerming
procedures clearly overlap, since a degerming procedure can be simultane-ously
treated as an antiseptic and vice versa.
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Microbiology and Immunology: Sterilizationand Disinfection : Definition of Frequently Used Terms in Sterilizationand Disinfection |