Physico-chemical characteristics of sodium hypochlorite are important for the explanation of its mechanism of action. The saponification, amino acid neutralization and chloramination reactions that occur in the presence of microorganisms and organic tissue lead to the antimicrobial and tissue dissolution process. The antimicrobial activity is related to bacterial essential enzymatic sites promoting irreversible inactivation by hydroxyl ions and the chloramination reaction. The organic dissolution action can be observed in the saponification reaction when sodium hypochlorite degrades lipids and fatty acids resulting in the formation soap and glycerol.