Does Isopropyl Alcohol Kill Germs?

Though the FDA has not cleared any liquid disinfectant that uses alcohol as its primary agent for use in clinical settings, isopropyl alcohol has proven effective at killing microorganisms under certain conditions, according to the Centers for Disease Control and Prevention. Among different types of alcohol available for sterilization, isopropyl alcohol is consistently one of the most bactericidal.

As reported by the CDC, clinical trials were conducted on methyl alcohol, ethyl alcohol and isopropyl alcohol to determine their relative effectiveness in sterilizing surfaces. All forms of alcohol suffered a significant drop in effectiveness when diluted to concentrations under 50 percent. None proved capable of killing bacterial spores or penetrating thick protein layers. Among the tested varieties, however, isopropyl alcohol did demonstrate an ability to kill the viruses for both hepatitis B and herpes. It was slightly more effective than ethyl alcohol at disinfecting both E. coli and S. aureus populations.

It was also found that isopropyl alcohol was effective in disinfecting reusable transducer heads. The CDC warns, however, that alcohol-based germicides are generally not recommended for sterilizing surgical implements. This is because none of the tested agents were able to reliably wipe out the spores of various bacilli, and fatal infections have occasionally been traced to the use of alcohol-treated implements.