Which of the following is an impoant disinfectant on account of effectively destroying gram positive and gram negative bacteria viruses and even spores at low pH levels: (A) Alcohol, (B) Hexachlorophene, (C) Phenol, (D) Chlorine
Answer is D. 1. Disinfection action of chlorine compounds is by release of free chlorine When hypochlorites are added to water , Hypochlorous acid is formed which is strong oxidizing agent and effective disinfectant Action is stable in even low pH. Hypochlorite (1%) used for used for routine serological disinfection, should not be used in presence of formaldehyde as it is carcinogenic. 2. Major limitations of chlorine compounds are that they are: Ineffective if used at an alkaline pH Less effective in the presence of excess organic matter Relatively unstable, especially if exposed to light.