Why is 70% alcohol solution a much better disinfectant than a 90% alcohol concentration? Wouldn’t a higher concentration mean better?

Question

Why is 70% alcohol solution a much better disinfectant than a 90% alcohol concentration? Wouldn’t a higher concentration mean better?

In: 5202

Answer 1

90% evaporates too quickly to be as effective – it will still disinfect, just not as completely. The 70% stuff takes a bit longer to evaporate, so longer exposure time means more time to do its job and therefore more effective.