Alcohol, particularly in solutions between 60% and 90% alcohol and 10 โ 40% purified water, is rapidly antimicrobial against bacteria, fungi, and viruses. Once alcohol concentrations drop below 50%, usefulness for disinfection drops sharply. Notably, higher concentrations of alcohol donโt generate more desirable bactericidal, virucidal, or fungicidal properties.
The presence of water is a crucial factor in destroying or inhibiting the growth of pathogenic microorganisms with isopropyl alcohol. Water acts as a catalyst and plays a key role in denaturing the proteins of vegetative cell membranes. 70%ย solutions penetrate the cell wall more completely which permeates the entire cell, coagulates all proteins, and therefore the microorganism dies. Extra water content slows evaporation, therefore increasing surface contact time and enhancing effectiveness.ย