DEFINITIONS
Disinfection
When an object is contaminated with so-called pathogenic germs it is said to be infected. To disinfect an object it is necessary to destroy the microörganisms. The destruction of all so-called pathogenic germs, whether in the substance of the object or on its surface, is called disinfection. All lower forms of animal and vegetable life are destroyed in sterilization, while in disinfection only the germs which, from the medical standpoint, are the cause of dis-ease, are destroyed. The agent used in disinfection is known as a disinfectant or germicide.
Sterilization
The destruction of all germ life in or on an object is known as sterilization. From the standpoint of hygiene sterilization is unnecessary except in dis-eases such as anthrax, tetanus, and other spore-bearing dis-eases, the spore being highly resistive and not so easily destroyed as the vegetative cells. Sterilization will disinfect but disinfection will not necessarily sterilize. Disinfection is thoroughly efficient in almost all cases. Sterilization destroys all life.
Antiseptic (Anti, against, and septos, putrid)
An antiseptic prevents putrefaction but does not necessarily destroy the microörganisms. A substance may act as an antiseptic by delaying or preventing the processes of decay and decomposition, but still not be a germicide. In other words, anything that will hinder the development of germ life acts as an antiseptic. Thus cold has a preservative action, although it will not destroy the microörganisms. A disinfectant may be diluted and used as an antiseptic. A 10% solution of formalin is a good disinfectant and will kill bacteria in a relatively short space of time, but formalin in a solution of one to fifty thousand will be a very good antiseptic. The germination of anthrax spores may be prevented by the use of bichloride of mercury in as weak a solution as one to three hundred thousand, but it will require a solution of one to one thousand to destroy the spores. A disinfectant is also an antiseptic but an antiseptic is not a disinfectant.
Asepsis
Asepsis is an absence of putrefactive bacteria. This may be accomplished without the use of germicidal agents by cleanliness which excludes all so-called pathogenic germs.