Why sanitizers with 95% alcohol aren't as effective as compared to the ones with 60%-70% alcohol.

Sanititzer's composition: 60%-70% (Isopropyl Alcohol /  Denatured Ethyl Alcohol)

Washing the hands with water and soap is being called the gold standard for hand hygiene. Still, practically it isn't possible to carry a personal sink everywhere. A small bottle of sanitizer can work wonders and is being used widely due to its effectiveness and portability.

The most common type of sanitizer uses Isopropyl Alcohol(Rubbing alcohol) or Ethyl Alcohol. Most of us think that we can consume ethyl alcohol aka ethanol but do remember, ethyl alcohol used in sanitizers is denatured(which means it includes a number of additives, thereby making it poisonous, unpalatable, and hence, undrinkable).



NOW THE QUESTION IS:

If a little alcohol is good at killing germs, Why stop at 65 or 70 per cent alcohol when you can go all the way to 100 per cent? Because it turns out 100 per cent alcohol is actually less effective at dealing with those cruel and wicked diseases.

• The simplest reason is the evaporation rate which needs to be capped otherwise the alcohol will vaporize without killing those germs, so the water content hinders the sudden evaporation of alcohol.    
• Using the 95% alcohol content makes skin dry and irritated                                                       
• Adding a few other ingredients, like hydrogen peroxide and glycerol, make the solution even more effective.                                                                               
• Isopropyl alcohol(Rubbing Alcohol) as compared to ethyl alcohol has a higher evaporation rate and hence the name.