When is it appropriate to use alcohol for disinfecting tools?

• A. When used at any concentration
• B. When a 60%-90% concentration is used
• C. Only when diluted with water
• D. Only on porous surfaces

Answer: (B)

Using alcohol as a disinfectant is most effective when applied in a concentration range of 60% to 90%. This concentration allows alcohol to effectively penetrate cell walls, disrupting cellular functions and leading to the breakdown of microorganisms. When the concentration is too low, the alcohol may not be effective in killing germs, while concentrations that are too high can evaporate too quickly, preventing adequate contact time with the surfaces or tools being disinfected.

Higher concentrations of alcohol, above 90%, tend to evaporate rapidly and may not provide the necessary contact time to achieve disinfection. Therefore, the recommended range ensures a balance where the alcohol can remain in contact with the surface long enough to destroy pathogens effectively.

The other options do not represent the most effective practices for using alcohol in disinfection. Using alcohol at any concentration does not ensure effectiveness, and diluting alcohol with water compromises its germicidal properties. Additionally, alcohol is not limited to porous surfaces; it is effective on non-porous surfaces where tools and equipment are usually handled.