Chemical Agent(s) | Mechanism(s) of Action |
Alcohols | Denaturation of proteins. Ethyl and isopropyl alcohols are most used; methyl alcohol has the weakest bactericidal action of the alcohols, so is seldom used for this application. |
Chlorine and chlorine compounds | Unknown, but might involve oxidation of sulfhydryl groups in amino acids (enzymes) ® oxidation of respiratory components, depressed DNA synthesis, decreased ATP production, etc. |
Formaldehyde | Alkylation of amino acid sulfhydryl groups of proteins and ring N atoms of purine bases. |
Glutaraldehyde | Alkylation of sulfhydryl, hydroxyl, carboxyl, and amino groups ® alteration of DNA, RNA, and protein synthesis. |
Hydrogen peroxide (H2O2) | Production of hydroxyl free radicals ® attack membrane lipids, DNA, and other essential cell components. |
Iodine and iodophors | Iodine penetrates cell walls quickly ® disruption of protein and nucleic acid structure and synthesis. |
OPA (ortho-phthalaldehyde) | Mechanisms similar to glutaraldehyde; less potent, but greater uptake through outer layers of myco- and gram-negative bacteria. |
Peracetic acid | Unknown, but believed to be an oxidizer ® denatures proteins, disrupts cell wall permeability, and oxidizes sulfhydryl and sulfur bonds in structural proteins, enzymes, etc. |
Phenolics | Low concentration: inactivation of essential enzyme systems and leakage of essential substances from the cell wall. High concentration: protoplasmic poison (penetration and disruption of cell wall, and precipitation of cell proteins). |
Quaternary ammonium compounds | Inactivation of energy-producing enzymes, denaturation of essential cell proteins, and disruption of the cell membrane. |