Hand sanitizer stations should contain at least __________% alcohol.

• A. 50%
• B. 60%
• C. 70%
• D. 80%

Answer: (B)

Alcohol-based hand sanitizers work by denaturing microbial proteins and disrupting membranes, and water is essential in this process. If the concentration is too high, there isn’t enough water to aid protein denaturation, and the sanitizer becomes less effective. If the concentration is too low, it may not reliably inactivate many pathogens. That’s why a minimum of 60% alcohol is recommended—it provides enough alcohol to disrupt microbes while still leveraging the beneficial effect of water. Higher concentrations like 70% or 80% are also effective, but the question asks for the minimum, which is 60%.