Action germicidal activity

Germicidal Properties. The germicidal activity of aqueous chlorine is attributed primarily to HOCl. Although the detailed mechanism by which HOCl kills bacteria and other microorganisms has not been estabUshed, sufficient experimental evidence has been obtained to suggest strongly that the mode of action involves penetration of the cell wall followed by reaction with the enzymatic system. The efficiency of destmction is affected by temperature, time of contact, pH, and type and concentration of organisms (177). 

Chlorine and chlorine-releasing compounds have been used in the disinfection of water supplies for more than a century. The di.scovery that hypochlorous acid (HCIO) is the active germicidal species that is formed when chlorine is dissolved in water led to the development and use of the first inorganic hypochlorite salts such as NaOCI and Ca(OCI) . Later, organic Af-chloro compounds were developed as disinfectants. These compounds release hypochlorous acid when dissidvcd in water, especially in the presence of acid. Two equally plausible mechanisms have been proposed for the germicidal action of hypochlorous acid the chlorination of amide nitrn-... 

Ethyl and isopropyl alcohols in concentrations of 50 to 70 percent by weight are often used. Alcohols are somewhat slow in their germicidal action, acting by denaturing proteins. However, they are effective disinfectants against lipophilic viruses. Adding 0.1 N HCl to the alcohol can increase virucidal activity. 

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