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

I use 70% alcohol for my mcology hobby. I’ve also used 90% alcohol. The rule of thumb is that things need to soak for three minutes and if you spray it on, 90% evaporates much too quickly. Other than that some are commenting on the mechanism of action where 90% causes cells to coagulate and protect themselves but I don’t know about that. IMHO 90% would work just as well if you reapplied it and waited the three minutes.