"Germs"

[The Atheist]

That's a common misunderstanding.

The immune system's most important component is the integument. This is the skin and the protection that surrounds its openings. Be mindful that the bowel is outside the body, not inside. There are some tissues that are sort of blendy, and these tend to be mucousy. Examples are salivary glands, eye sockets, ENT surface, lung surface, lactating nipples...

Some particles can colonize these exterior surfaces, but are not a problem until they penetrate through a wound. Again, tetanus is a good example. Others can infect via mucous membrane, but are not a problem unless you are exposed to a minimum threshold concentration of them. A common mechanism for infecting a mucous membrane is that your completely protected finger gets covered in a minimum threshold concentration and then you stick it in your eye, nose or mouth for god knows what reason. Handwashing reduces the number of particles on the finger, and reduces the risk of infection through these primary routes.

Granted, mucous is awash with IgA antibodies, but they are rarely specific immunity. ie: they bind to anything and if it's an infectious agent, they may neutralize it out of sheer luck.

So, no: we're not 'immune' to these pathogens. We are, however, protected by our integument barrier and mucous under normal circumstances, and by good hygene.

Beautifully put.

It takes at least 30-60 minutes to cold sterilize anything with the most potent disinfectants and it requires the item be submersed in the disinfectant. So there is no way any of these products kill everything so thoroughly on contact.

As for how the advertisers get away with the claims, I need to do more investigating.

I reckon the advertisers get away with it by being very creative with how you define both "kill" and "germ".

I will, however, take issue with the 30-60 minutes. Hypochloritic acid tends to annihilate almost all types of viruses and bacteria on contact; I doubt there'd be any more effectiveness reached after the first second or two. (Not much use as a hand sanitiser.)

 

[Eos of the Eons]

Blue flame wouldn't make it as a hand sanitizer either, but it does kill ALL microbes AND the nasty spores of spore bearing types when you burn them in it for the prescribed amount of time.

Yah, I liked the flaming in microbiology class.

 

[Skeptic Ginger]

I will, however, take issue with the 30-60 minutes. Hypochloritic acid tends to annihilate almost all types of viruses and bacteria on contact; I doubt there'd be any more effectiveness reached after the first second or two. (Not much use as a hand sanitiser.)

This is not consistent with actual practice in sterilizing equipment for medical procedures.

Guidelines for Sterilization & Disinfection is a typical infection control recommendation based on actual practice. And it looks like even the 30 min recommendation is frowned upon. I'm not surprised.

High level disinfection will kill most vegetative microorganisms but will not kill the more resistant bacterial spores. Commonly used disinfectants such as alcohol, iodophors, quaternary ammonium and phenolic compounds are not effective sterilants and, therefore, are not acceptable for use on items intended to be used in survival surgical procedures.

Cold (chemical) sterilization used properly. Effective and proper use of cold sterilization is dependent on many factors including:

* The use of chemicals classified as "sterilants". Those classified only as "disinfectants" are not adequate.
* The physical properties of the item being sterilized. It must be relatively smooth, impervious to moisture, and be of a shape that permits all surfaces to be exposed to the sterilant.
* Adequate exposure to all surfaces, both interior and exterior. Tubing must be completely filled and the materials to be sterilized must be clean and arranged in the sterilant to assure total immersion. The items being sterilized must be exposed to the sterilant for the prescribed period of time.

#Cidex: Active ingredient: 2% Glutaraldehyde. The manufacturer's instructions indicate that a minimum of 10 hours is required for sterilization....
#Clidox: Active ingredient: Chlorine dioxide. 1:5 mixture must be mixed daily. 1:18 mixture is good for 14 days. 1:5 is a good sterilant; 1:18 is a disinfectant.
#Alcide: Active ingredient: Sodium hypochlorite 1.37%. The manufacturer's instructions indicate that a minimum of 6 hours is required for sterilization....
#Other acceptable sterilants are the following chemicals classified as sterilants by the Centers for Disease Control (CDC). These are the chemical ingredients of some of the commercial sterilants:
* Glutaraldehyde (2%) for a minimum of 10 hours.
* Formaldehyde (8%) / Alcohol (70%); minimum of 18 hours.
* Stabilized hydrogen peroxide (6%) for a minimum of 6 hours.

I'll see what other sites say about the time one needs for chlorine dioxide. I'm not familiar with that one.

Of course if you want to talk about 100% hypohlorite or some equivalent of the blue flame in Eos's post, you might be right. But destroying the thing you are sterilizing is not what we are talking about here.


It looks like the commercials are getting away with the claims by not mentioning their ineffectivenesses against spores. TB bacteria and hepatitis B virus are also hard to destroy. So it may also be the commercials are counting those as .01% of the "germs" on contact. I suppose the worst pathogens probably do not account for a large % of the total organisms.

 

[Skeptic Ginger]

Chlorine Dioxide

Chlorine Dioxide (Clidox®, Alcide®)

A minimum of 6 hours required for sterilization. Presence of organic matter reduces activity.

I think you are confusing disinfecting with sterilizing.

 

[The Atheist]

Chlorine Dioxide

I think you are confusing disinfecting with sterilizing.

No, but if a 1.3% solution is being used, that might explain it - that's reasonably weak.

 

[Skeptic Ginger]

No, but if a 1.3% solution is being used, that might explain it - that's reasonably weak.

Household bleaches usually contain sodium hypochlorite in a 3% to 6% solution. Even at that low concentration, bleach is extremely caustic. So like I said, if you are talking about destroying the object or surface you are killing the microbes on, then sure, you can sterilize things faster than an hour. That is not what was being discussed. I can assure you, however, 1.3% hypochlorite is not 'weak'. Care to make a mouthwash out of the 3% bleach that comes straight out of the laundry jug? Want to soak you hands in it for 5 minutes?

 

[ectoplasm]

Having read this entire thread, and parts of it twice, is it safe to say that alcohol based hand sanitizers are useless against the kind of pathogens (virus that cause colds, influenza and norovirus) that we are trying to protect ourselves against?

I have a friend who is an ex-public health nurse. Now that she has kids she has turned into the classic over-protective mom. She is building a new house and insisting on soapstone counter tops because it is anti-bacterial. I'd never heard that before. It seems redundant as she bleaches down her counter tops several times a day anyway.

 

[quarky]

As was pointed out, most 'germs' are not pathogens. Random killing of the benign bacterium can cause other problems, such as fungal infections.

 

[Eos of the Eons]

I just feel there are cases where using hand sanitizers (alcohol or otherwise) shows benefits.

The kinds of pathogens it can kill do cause recurring illnesses. Schools and hospitals are places filled with people carrying illnesses around. Hospitals are fighting MRSA.

Places where large numbers of people can get confined, like cruise ships, hospitals, and classrooms, appreciate when those illness rates are cut down (particularly bacterial).

The studies back that part up.

It has been shown to be beneficial. We don't want to kill all microbes, as we don't want increased fungal infections, but there haven't been increases in fungal infections due to the use of this product. I personally don't see how hand sanitizer will increase fungal infections, since you don't kill off the bacteria on all parts of your body, you just end up targetting the ones on your hands.

It's not meant to be a wonder-killer, so yeah, saying it kills 99.9% of germs may be too ambiguous, and that is why they can say it, but that has misled people in this thread even. Marketers are shooting themselves in the foot then.

In places where it is most used now, it does help though. Marketers therefore need to prove the benefits in their marketing more clearly. I have nothing to gain from its acceptance. I have just worked in schools and hospitals over the past year and can understand why the stuff is being used. Maybe it will help cut down gastrointestinal (food poisoning) diseases in the home too. One study showed that possibility. And you won't end up with super bugs. Win-win.

I just don't want to see the product unfairly dismissed altogether. I feel it is better than silly antibacterial soaps and other products that could potentially just leave the super bugs behind for us to contend with.

 

[The Atheist]

Having read this entire thread, and parts of it twice, is it safe to say that alcohol based hand sanitizers are useless against the kind of pathogens (virus that cause colds, influenza and norovirus) that we are trying to protect ourselves against?

Not too sure about cold and influenza viruses, but they are definitely useless against norovirus.

I have a friend who is an ex-public health nurse. Now that she has kids she has turned into the classic over-protective mom. She is building a new house and insisting on soapstone counter tops because it is anti-bacterial. I'd never heard that before. It seems redundant as she bleaches down her counter tops several times a day anyway.

I agree. It also sounds pretty OCD-type behaviour to bleach several times a day. I know wood has anti-bacterial properties, but I've never heard a claim for stone. Bloody awful stuff for benchtops, I would have thought - pretty easy to mark.

 

[blutoski]

I just don't want to see the product unfairly dismissed altogether. I feel it is better than silly antibacterial soaps and other products that could potentially just leave the super bugs behind for us to contend with.

I think that's a good takeaway summary for anybody scanning the thread.

* washing: necessary
* alcohol gel sanitizers: probably better than washing; absolutely better than nothing
* antibacterial soaps: avoid

 

[The Atheist]

I think that's a good takeaway summary for anybody scanning the thread.

* washing: necessary
* alcohol gel sanitizers: probably better than washing; absolutely better than nothing
* antibacterial soaps: avoid

Nope, I can't agree with "probably better than washing".

Proper handwashing and drying: (which I'm surprised hasn't been mentioned yet - dry your hands on a dirty towel, may as well not bother) is clearly the best option.

Alcohol-based sanitisers - definitely better than nothing, but not a complete defence, nor as good as a serious hand wash.

 

[Skeptic Ginger]

It's pretty hard to avoid antibacterial soaps. While they are not necessary in the home, you can't find many hand soaps these days (in the US anyway) that do not contain triclosan.

I decided that was not a battle I wanted to waste any of my time on.

 

[Skeptic Ginger]

Not too sure about cold and influenza viruses, but they are definitely useless against norovirus.

Interesting, the CDC does not agree with you, nor does the State of Virginia's public health dept. However, the Michigan dept of public health does. The Virginia PHD article explains the problem.

A Randomized, Controlled Trial of a Multifaceted Intervention Including Alcohol-Based Hand Sanitizer and Hand-Hygiene Education to Reduce Illness Transmission in the Home says

The observed effect of alcohol-based hand sanitizers on the transmission of GI illnesses in this study is consistent with known data. Previous studies have suggested that rotavirus (the most common cause of GI infection in the child care setting) is not removed effectively by routine handwashing with soap and water, whereas alcohol reliably kills the virus.21,58,59 Noroviruses may be killed less efficiently by alcohol-based products,44 although fewer data exist regarding this issue because noroviruses cannot be grown easily in culture systems. Although the CI for the IRR is wide, reflecting the relatively low number of secondary GI illnesses observed during our study, the upper limit is <1.0 and the reduction in illness transmission is statistically significant. Even if the true reduction in GI-illness transmission is lower than our point estimate of 59%, it remains clinically important because of the enormous number of intestinal infectious diseases in the United States, which may approach 100 million cases annually, and because of their cost, which has been estimated at $23 billion per year in health care expenditures and lost productivity.60

This article has a lot more re reviews of the use of alcohol as a disinfectant against a number of additional organisms.


While not organism specific, this meta-analysis A systematic review on the effectiveness of alcohol-based solutions for hand hygiene, found the hand gels effective.

The use of alcohol has been proposed as an option for hand hygiene. A systematic review was conducted to evaluate the clinical evidence supporting the use of alcohol-based solutions in hospitals as an option for hand hygiene. Studies published between January 1992 and April 2002 in English and Thai, related to the effectiveness of alcohol-based solutions, were reviewed. The databases searched included Medline, DARE, CINAHL and Dissertation Abstracts International. All studies were assessed as having adequate methodological quality. Results of this systematic review supported that alcohol-based hand rubbing removes microorganisms effectively, requires less time and irritates hands less often than does handwashing with soap or other antiseptic agents and water. Furthermore, the availability of bedside alcohol-based solutions increases compliance with hand hygiene among health care workers.

 

[Skeptic Ginger]

The research on norovirus may be forthcoming. My lab is advertising they have a new procedure to culture the virus. But it'll most likely still be a couple more years.

 

[The Atheist]

Interesting, the CDC does not agree with you,

That is interesting, because they are in a serious minority view.

I'll trump the CDC with the EPA, whose comprehensive list of disinfectants effective against norovirus, include only sanitisers with chlorine compounds - not one alcohol-only gel.

I'll have a bet the CDC has just made a simple oversight on this one.

nor does the State of Virginia's public health dept.

I note that alcohol-based sanitiser is recommended "when no handwashing facility is available".

However, the article does note: "The reliability of disinfectants other than those containing chlorine to kill norovirus is uncertain, so that the use of hypochlorite solutions is recommended for use whenever possible."

Michigan dept of public health does. The Virginia PHD article explains the problem.

Smart people in Michigan.

While not organism specific, this meta-analysis A systematic review on the effectiveness of alcohol-based solutions for hand hygiene, found the hand gels effective.

Pretty vague stuff really - I'd need to see the full article to make any comment.

Also to throw into the mix:

University of North Carolina, (page 40) using calicivirus as a surrogate norovirus found that ethanol gel is only effective after 10 minutes' immersion. That would make 20 seconds of rubbing it on your hands fairly useless. Note also that that was 75% alcohol solution - 50% stronger than most gels.

 

[Dogdoctor]

So the question is what percentage of germs is norovirus? My guess is less than .002 % so the claim is likely good.

 

[casebro]

From Skeptgirls post #54 above:

"Furthermore, the availability of bedside alcohol-based solutions increases compliance with hand hygiene among health care workers."

None of the studies we've seen here separate the better hand hygiene from the actual use of the alcohol rubs. And with out that separation, there is no evidence that the alcohol does anything beneficial.

My summation: The brightly colored plastic dispensers make excellent reminders to use good hand hygiene.

 

[robinson]

Historical note. It was midwives washing their hands, and one observant Doctor, that led to the discovery of germs, and how they caused infections.

They just used soap, which was enough to reduce infections dramatically.

That makes me wonder, has there ever been a topic on Semmelweis? That poor dude went through hell over this same issue.

 

[The Atheist]

So the question is what percentage of germs is norovirus? My guess is less than .002 % so the claim is likely good.

That's a fair point, too.

When there's no outbreak within your circle of movement, you aren't going to have any on your hands, and yes, they would be a tiny minority of all "germs".