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.

Insecticide

An insecticide is an agent capable of destroying insect life. Many of the germicidal agents are also insecticides. There is a great difference in the resistance of different insects. Formaldehyde is a good germicide but is not an insecticide. There are four ways of using insecticides. In liquid form, powder, vapor form and those placed in food to be eaten by the insects.

Germicide

A germicide and a disinfectant are the same for they both destroy germ life. Many germicides are so powerful that they completely sterilize or destroy all life.

Deodorant

A deodorant is not in any sense a disinfectant and has no power to destroy germ life. It is an agent which neutralizes unpleasant odors. A disinfectant destroys germs but does not necessarily destroy odors. A deodorant must not be confused with a substance having pungent odor which merely substitutes one odor for another. A deodorant destroys the unpleasant odor.

Fumigation

Fumigation is a means of disinfection by use of fumes or gases, and is used generally for the purpose of destroying germ life only on the surface of objects. For this reason fumigation should not be used as a substitute for disinfection. Formaldehyde and sulphur dioxide are used largely for fumigating purposes.

Of these two gases formaldehyde is the better since it is not poisonous, does not injure the surface of objects and will not damage the most delicate fabrics nor destroy colors. Sulphur dioxide is very destructive and therefore less desirable. However, all the gaseous agents lack sufficient penetrative power to accomplish more than a surface disinfection. Formaldehyde is a good germicide and this adds to its efficiency.

To obtain the desired results in fumigating there must be special attention given the preparation of the rooms or spaces to be fumigated. All objects in the room should be so exposed that the gas may readily get to all surfaces. All furniture and other objects should be moved into the room away from the walls and all doors and drawers of bureaus and boxes should be opened so the gas may find free access to every nook and corner. Much of the gas may escape through cracks and crevices, therefore special care must be exercised that these openings are all properly closed before the fumigation is started. In view of the fact that the gas is non-destructive there is no harm done even to the most delicate materials.

The best results are obtained from the formaldehyde when the temperature of the room is 65° F. or over, with a relative humidity of at least 60%. While formaldehyde has the power to kill spores it is not considered sufficient to disinfect in such dis-eases as anthrax and tetanus.

Formaldehyde gas kills all forms of microörganisms almost instantly but is not particularly destructive to higher form of life. It produces a marked irritation in the mucous membrane of the respiratory tract which may result in death to animals exposed to the gas for any length of time. It is not considered an insecticide.

In fumigating a room with formaldehyde great care must be exercised that the individual does not remain in the room after the gas begins to be liberated. After the process of fumigation has been completed the windows and doors should all be opened that the gas may escape. It is always best to have the doors and windows open from the outside so that it will not be necessary for any one to go into the room until the gas has blown out.