Factors Influencing the Antimicrobial Activity of Chemical Agents

Factors Influencing the Antimicrobial Activity of Chemical Agents

The following factors will affects the activity of a disinfectant or antiseptic and these should be borne in mind during use.

a. The Concentration and kind of a chemical agent used

The higher the concentration of the germicide the greater will be the rate of killing. This is particularly important with the phenolic group of compounds, whose activity falls off very rapidly with dilution.

b. Time of exposure to the agent

In general germicidal activity is increased with time and a sufficient exposure is imperative for efficient disinfection.

c. Temperature at which the agent is used

An increase of temperature will also raise the rate of killing.

d. Presence of Organic matter

Most germicides are reduced in activity by the presence of organic matter and particularly by the presence of proteins such as those in body fluids.

e. Number of organisms present

The larger the number of organisms, the greater will be the time required for disinfection.

f. The kinds of microorganisms present - Presence of spores

Spores are exceptionally resistant to the great majority of disinfection.