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There are plenty of different hand soaps out there, as well as hand sanitizers. Is there an advantage to soaps that claim that they're antibacterial vs soaps that just say soap?

In particular I'm looking at Softsoap who offers normal soap and antibacterial soap.

Examples:

Normal:

Regular Softsoap

Antibacterial:

Antibacterial Softsoap

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Short answer: There is no benefit for their use in households.

Long answer: These soaps (see here for the complete list) contain the so called quaternary ammonium compounds Benzalkonium chloride and Cetrimonium chloride which indeed have antimicrobial properties.

While they do not promote resistance to these compounds (see reference 1), their use is still not recommended, as their permanent use might dry out the skin, can cause contact allergies and the products released into the environment are also problematic.

There are two studies, which compared the use of normal soap (which has some antibacterial properties on its own) to antibacterial soaps in household environments and found no differences. See article linked in reference 2 for a summary and references 3 and 4 for details on the studies.

This doesn't mean that antibacterial soaps are useless at all, they simply make no sense in households. For hospitals or doctors they are an important tool to protect their patients before operations. But here detailed instructions for how long and how the hands have to be washed are provided. Hand washing is also followed by another disinfection step, which helps with efficiency. But this is very much different from the way people wash their hands at home. See reference 5 for some opinions here.

References:

  1. Use of germicides in the home and the healthcare setting: is there a relationship between germicide use and antibiotic resistance?
  2. Plain soap as effective as antibacterial but without the risk
  3. Consumer antibacterial soaps: effective or just risky?
  4. Effect of antibacterial home cleaning and handwashing products on infectious disease symptoms: a randomized, double-blind trial.
  5. The Burning Question: Is It Safe to Use Antibacterial Soap?
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  • $\begingroup$ Thanks for the link, updated my answer to discuss other members of the Softsoap antibacterial series. $\endgroup$ – March Ho Jun 22 '15 at 20:19
  • $\begingroup$ If there is no difference between the normal soap and "antibacterial" ones, what benefits do hospitals get by using it? $\endgroup$ – WindowsMaker Jun 22 '15 at 22:37
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    $\begingroup$ @zaftcoAgeiha They make no sense in households. I clarified the answer. The thing is different in hospitals with people which have systematically learned how to disinfect their hands. $\endgroup$ – Chris Jun 23 '15 at 5:24
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Chris has correctly identified the antibacterial agent in the hand soap depicted in the image in the question, and therefore his answer is superior as a direct answer.

Nevertheless, other members of the Softsoap series of hand soap uses triclosan, 0.15% as their antibacterial agent, as seen in an image of their ingredient list on the reverse of the bottle.

(click for enlarged image)

enter image description here

Triclosan has been shown to be effective by Webster et al (1992) in reducing the incidence of MRSA infection as well as being milder to the skin as compared to chlorhexidine gluconate in a neonatal ward.

The average number of new cases of MRSA per week was reduced from 3·4 to 0·14 (P < 0·0001) in the experimental ward whilst no significant changes occurred in the control ward.

Triclosan has also been shown by Jones et al (2000) to be effective on a large variety of different bacterial, viral and fungal strains.

enter image description here

enter image description here

enter image description here

Therefore, the usage of triclosan is effective as an antibacterial agent, and would likely result in less bacteria on the hands after washing.

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    $\begingroup$ The depicted softsoap product do not contain triclosan but beanzalkonium chloride. See here (you have to scroll down). $\endgroup$ – Chris Jun 22 '15 at 20:16
  • $\begingroup$ @Chris but most antibacterial soaps, these days contain triclosan. Tertiary ammonium salts are a bit harsh. $\endgroup$ – WYSIWYG Jun 23 '15 at 3:59
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    $\begingroup$ I'd note that less bacteria on your hands is not necessarily a good thing. The natural microbiome on your hands has noticeable protective effects. $\endgroup$ – Jack Aidley Jun 23 '15 at 11:00
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    $\begingroup$ @Jack Aidley Although your comment cannot answer the question, I think it's the best viewpoint that we can have with repect to the matter. $\endgroup$ – Rodrigo Jun 23 '15 at 12:34
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    $\begingroup$ Using triclosane is a very bad idea. Microbes become resistant to it, and there is cross-resistance between triclosane and some antibiotics e.g. chloramphenicol and tetracycline. Here is a summary in the topic: ncbi.nlm.nih.gov/pmc/articles/PMC4295542 Afaik. most MRSA is already resistant to it and they grow much better with triclosane, because the antibiotics kills competing species. So I think your answer and your references are outdated, a lot of things happened in the last decades... $\endgroup$ – inf3rno Jun 24 '15 at 15:56
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You may be interested to look into the Old friends hypothesis, since this is related to how the human immune system may respond to reduced biodiversity in the microbiota. The basic idea is that the human immune system is developed by exposture to the microbiota, and without exposture to organisms from our evolutionary past, immune system regulation might fail. This can then lead to poorly regulated inflammatory responses and maybe allergies or other chronic inflammatory diseases. Since the exposture to our evolutionary Old friends is lower in developed countries and urban areas, this hypothesis might potentially (partially) explain the increased prevalence of allergies in developed countries. Even though it is somewhat tangential to your question, and does not directly answer the question of the pros and cons of antibacterial soap, it should still be relevant for a more general case.

Two good starting points are Rook (2013) and Hanski et al (2012). Rook (2013) is a general overview of the theory with many good references to empirical studies that relate to the hypothesis, by one of the main proponents of the theory. Hanski et al (2012) is an interesting epidemiological paper, where they relate the allergic disposition of individuals to both the general biodiversity in their larger living environment as well as the generic diversity of their skin microbiota. In the paper, they find a positive relationship in healthy individuals between immune responses and the abundance of the gammaproteobacterial genus Acinetobacter on the skin, but they do not find the same pattern in atopic individuals. The study also finds a negative relationship between the environmental biodiversity close to the homes of study subjects and the frequency of atopy (so high biodiversity -> lower levels of atopy).

To be clear, this is still a hypothesis that needs further testing and support. However, there are many interesting case studies that can lend support to it, and indicate plausible mechanisms.

References:

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Probably, it is worth to add some historic (and ironic) "perspective" to this question. It will probably explain that even without scientific research the answer to this question is probably "no" and that real use of bacterial soap should probably be reduced to hospital settings and not expanded to households as suggest promotions and commercials.

The historic perspective I wanted to add relates to the book "The Hermit in the Garden" by Gordon Campbell. Here live hermits are described (there were non-alive as well, this is why I call these "live"). Campbell cites another book - "Sir William Gell's A Tour in the Lakes Made in 1797":

"the hermit is never to leave the place, or hold conversation with anyone for seven years during which he is neither to wash himself or cleanse himself in any way whatever, but is to let his hair and nails both on hands and feet, grow as long as nature will permit them."

From this "work" description we can speculate that "dangerous" infections were not expected during such a long period of soapless live. This is why we could assume that any soap is probably of limited "antibacterial" value for otherwise healthy person.

(Remark: This "exclamation" not trying to answer the question in a scientific way, but just to add some "color" to the question and the answers posted. I hope, it is worth to place it here instead of a comment).

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    $\begingroup$ Remember though, that they are living in isolation, they won't come in contact with as many bacteria or viruses as the general population. It's not like they will come in contact with sick people if they are living more or less in isolation. Besides, what viruses and bacteria are there they will adapt to especially if they are healthy individuals. However, I do appreciate the insite. $\endgroup$ – SolarLunix Jun 28 '15 at 9:50
  • $\begingroup$ @SolarLunix They lived in gardens, their isolation from sick people were not absolute and contact with all the mosquitoes, flies, worms, dogs etc had to increase the exposure to multiple pathogens. I suppose it is interesting point to start with. $\endgroup$ – Ilan Jun 28 '15 at 9:55
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Human immune defense response is primed by cell damage products as it does not have prior knowledge about bacterial or viral "malware".

The whole purpose of disinfectant substances is damaging cells and potential organic disease carriers. As those substances are not discriminating, frequent use of them will prime your immune defense against benign organic matter as well. In combination with solvents that remove protective layers of fat and thus increase the permeation of this kind of cell waste into top skin layers, this sounds like a recipe for allergies and neurodermitic reactions in the long run.

There is a high correlation of countries (and eras) with high standards of living including household hygiene and autoimmune response problems. Finding actual causations is work in progress.

While that is still the case, it is my gut feeling that contact with disinfectants should be reserved to cases of tangible risk.

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    $\begingroup$ Interesting answer. Can you please add some references to it? $\endgroup$ – Chris Jun 23 '15 at 13:35
  • $\begingroup$ Apart from references, I found your answer a little hard to read, could you please try to add a summery such as "Antibacterial soap doesn't help because..." ? $\endgroup$ – SolarLunix Jun 23 '15 at 15:15
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    $\begingroup$ This is an interesting answer, but this kind of stuff will get you a lot of downvotes. The thing to remember about this site (and it is aggravating, and not very well stated) is that "it is not a forum." Answers are supposed to be very definite with reasons spelled out in detail, and supposition and comments about the question are suppoosed to go in the short comments. $\endgroup$ – chronometric Jun 24 '15 at 3:06
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    $\begingroup$ That being said, I was unable to find any studies showing that Benzalkonium chloride caused over-sensitivity of the immune system to benign agents. I think you have generally the right idea, but most of your facts seem to be unfounded theories(?). Like others said, these things need references or clear statements that they're guesswork (in which case they're probably inappropriate for empirical discussions like this). $\endgroup$ – chronometric Jun 24 '15 at 3:14

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