Alcohol in Mouthwash

What is the purpose of alcohol in mouthwash? Crest mouthwash is alcohol free and therefore I would think that it is a non-essential ingredient. If it is non-essential, why did they put alcohol in mouthwash in the first place?

Alcohol is an antiseptic that kills some of the germs that promote gingivitis, bad breath, and cavities. In fact, Listerine was named after Joseph Lister who invented antiseptic medical procedures. Alcohol was included in early mouthwashes because it is abundant. Ethanol, the alcohol used in mouthwashes, is the same alcohol that people drink. Because of that, it is not uncommon to hear of young people and alcoholics using mouthwash to get drunk.

Newer mouthwashes take advantage of more modern antiseptic ingrediants and don’t need the alcohol.

I’m curious about this, too. My WAG? The supposed benefits of its antiseptic properties, and the sting makes it feel like it’s doing something.

I have the exact opposite question, and hope it doesn’t constitute a thread hijack, but what is it in this new Crest mouthwash that kills 99% of germs without alcohol?

Mainly, what can get listed as “effective” and “active ingredient” isn’t always so, and the rules are pretty damn stringent. Most likely, most of the actual effectiveness of Listerine comes from alcohol, and the alcohol-free mouthwashes do very little if anything. However, measured effectiveness using controlled experiments will show that most of it comes from antibacterial/antiseptic additives, and alcohol is there as an “inactive ingredient”.

The active ingredient in Crest Pro-Health Rinse is cetylpyridinium chloride, a long-used ingredient in some anti-bacterial solutions for the mouth and nose. It’s also been used as a preservative, though I don’t know how good it is at that. It’s been in Scope forever, and it’s in the same chemical class as benzalkonium chloride, which we’ve discussed here before.

Those two statements don’t really support each other. What makes you think that the controlled experiments are not reliably demonstrating the effectiveness (or lack thereof) of alcohol?

I do not believe this to be true.

I recall reading somewhere that the alcohol in mouthwash provides a better solution for mixing the ingredients. In other words, when some alcohol is added to mouthwash, all the other ingredients will be “well mixed” and remain suspended in the solution for an indefinite period of time.

Perhaps a chemist will chime in and back me up with some technical mumbo-jumbo…

My last two dentist visits, one in California and one in Korea, had both dentists telling me to use alcohol-free moutwash. They both said that moutwashes with alcohol are counter-productive as they don’t kill the nasties that promote bad breath etc. but do kill the stuff you need. Consequently, I’ve been using a variety of boozeless mouthwashes for a while now (yes, it’s been some time between dentist visits). Currently, I’m using the aforementioned Crest moutwash and not only I, but people I know, tell me that it’s working.

So kids have something to get a “buzz” off of at band camp.


Now that I think of it, rubbing alcohol has another directed use as a mouthwash. So would that mean a higher concentrated solution of alcohol is more effective?

Either it’s a clever marketing scheme by Crest, a parent-dentist conspiracy to keep kids away from anything remotely containing alcohol, or there really is something to the alcohol vs non-alcohol mouthwashes.

I’ve tried that Crest mouthwash, and it’s awful. Not only is it treacly-sweet because of the lack of alcohol, but bubbles up so much that I have a hard time keeping my mouth closed as I swish it around. And when I attempt to gargle, bubbles come up out of my mouth like a cartoon character who swallowed some soap.

How about hydrogen peroxide? I know the question of its usefulness in cleaning the mouth has been answered in other threads; but what happens if you swallow the stuff?

While it isn’t likely that anyone could swallow a mouthful accidentally, plus it is somewhat diluted by water and saliva, some of it can still trickle down the throat, right?

I suppose the stomach acids will take care of it.

Consumer-available H2O2 has been diluted to about 3%. It seems to me that while you shouldn’t go chugging the bottle, a small amount swallowed should not cause a problem. I don’t know what the possible free radicals could do to your espohagus and other cells, though.

Are you sure about that? All the rubbing alcohol bottles I’ve seen specifically say stuff like “for external use only” and “poison”. Not something that you want to be putting in your mouth.

Rubbing alcohol contains isopropyl alcohol rather than ethanol (the kind you can drink). It is certainly not a good idea to drink rubbing alcohol although many have done it. It can cause all kinds of nasty effects including severe gastric disturbances.

Here’s the MSDS for 70% isopropyl alcohol (rubbing alcohol). Definitely not something to be swishing your mouth out with. The vapors alone are bad for you.

I’ve read (I think from Consumer reports) that one shouldn’t buy a mouthwash without the ADA stamp on the bottle. I also understand that alcohol is the ingredient that helps dental desease.
(ADA = American Dental Assoiation)

On second thought, it was hydrogen peroxide, rubbing alcohol’s “twin”. Incidently, I never used hydrogen peroxide orally.

So since it’s been brought up, why would one type of alcohol be safe and effective for gargling with while the other is poison.

Once as a child, I swallowed mouthwash (that ACT for kids or whatever it was). It was Christmas Eve, I was all keyed up, and I forgot to spit it out. On the bottle, it said a mouthful wouldn’t hurt, but to drink milk for some reason.

What would be the purpose of drinking milk?