Does rubbing alcohol sterilize when it evaporates, or when it's wet?

[Subway Prophet]

Someone told me at a very young age that rubbing alcohol does all its magic when it evaporates. Microbes that become infused with alcohol suddenly burst apart when the alcohol boils away at room temperature, or something like that. Is this hokum?

The more I think on it, it makes sense to me that alcohol does a lot of damage when it's wet. It seeps into cracks better than water does, and I imagine that a microorganism losing its water mass to alcohol has to incur some damage from the process.

So how does rubbing alcohol work?

[x-ray vision]

It has nothing to do with evaporation. Alcohol kills bacteria by dissolving their cell walls and membranes.

[picunurse]

Actually, the alcohol enters the cell wall, and as it evaporates the cell is crenated (dried out), breaking the walls down.

[x-ray vision]

Actually, the alcohol enters the cell wall, and as it evaporates the cell is crenated (dried out), breaking the walls down.
I have never heard that before. A quick Googling has only given me one hit me mentioning evaporation as being responsible for killing bacteria, but the rest have been along the lines of "Alcohols mode of action is to denature membranes which results in cellular leakage."

[astro]

Why does rubbing alcohol kill bacteria? (Disrupts their cell membranes) (http://www.scienceupdate.com/newsite/show.php?date=20050505#)

[spingears]

So how does rubbing alcohol work?Doesn't.

Ethyl Alcohol Does (http://www.google.com/search?hl=en&q=how+alcohol+kills+germs&btnG=Google+Search)

"Ethyl alcohol kills germs by denaturing their protein, which means that germs cannot "mutate" or suddenly become resistant to ethyl alcohol and not be killed by it. Ethyl alcohol has been used to kill germs for centuries now, and no organisms are known to be resistant to it."

[groman]

Doesn't.

Ethyl Alcohol Does (http://www.google.com/search?hl=en&q=how+alcohol+kills+germs&btnG=Google+Search)


You're going to have to come up with a cite that says Isopropyl Alcohol does not kill germs. I'm fairly sure methanol, ethanol and isopropanol are all virtually absolute disinfectants to which no resistance can form. Much like chlorine bleach.

[Colibri]

Doesn't.

Does, according to your own link.

Ethyl Alcohol Does (http://www.google.com/search?hl=en&q=how+alcohol+kills+germs&btnG=Google+Search)

All that is is a page of Google hits. Did you even read more than one? Several of them say specifically that isopropyl alcohol, as well as ethanol, kills bacteria. In any case, rubbing alcohol can also be made of denatured ethanol.

From your third link:

Rubbing alcohol as an antiseptic

There are two general types of rubbing alcohol, one made primarily from ethyl alcohol (ethanol) and the other from isopropyl alcohol. Both kill bacteria okay but are less effective on viruses.

From your sixth link:

Ethyl alcohol (ethanol) and isopropyl alcohol are frequently used for chemical disinfection. They are mainly used as skin antiseptics and act by "denaturing" or altering the molecular structure of bacterial proteins, destroying the cell. Alcohols kill vegetative forms of bacteria but have no action on spores or viruses.