Why 70% alcohol is used as a Disinfectant? (2024)

There are several reasons why 70% isopropyl alcohol is used as a disinfectant. First, it has been found to be more effective at killing microorganisms than higher concentrations of isopropyl alcohol. This is because the water content in the 70% IPA solution allows for better penetration into the microorganisms and denaturation of proteins.

On the other hand, solutions with lower alcohol concentration (less than 50%) are not as effective against microorganisms, while those with higher concentration (above 90%) evaporate too quickly, leaving insufficient contact time to penetrate the cell wall of the microorganism.

Another reason why 70% isopropyl alcohol is preferred as an alcohol disinfectant is that it is less volatile than higher concentrations, making it easier to handle and safer to use. Additionally, 70% isopropyl alcohol is less likely to cause skin irritation or damage to surfaces, compared to higher concentrations.

Overall, the 70% concentration of isopropyl alcohol strikes a balance between its antimicrobial effectiveness, ease of use, and safety, making it an ideal choice for disinfecting a wide range of surfaces and equipment in healthcare, laboratory, and household settings.