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As a germophobic, I almost consume a soap bar each day due to the touch of a door handle or other daily used items around the house. This is instigated due to OCD perhaps.

This is unhealthy and bad for the skin (As using too much is harmful and thus there needs to be some control over the issue. One proposed by someone was that just washing the hands by water and not consuming the soap.

Would washing hands with only water be equally effective in most common cases?

Sklivvz
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Haider
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    While interesting, this doesn't seem like a [notable claim](http://meta.skeptics.stackexchange.com/questions/864/faq-must-all-questions-be-notable) and should probably be closed. – Zach Mierzejewski Jan 07 '16 at 16:09
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    I would think the toweling off afterwards, might affect some of the oil removal that the soap would've done. Also, I think this should remain open as this claim can be rephrased as 'You must wash your hands with soap and water to effectively clean your hands'. Which a notable claim. – jmathew Jan 07 '16 at 16:34
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    An interesting twist to this: as a germaphobe that is constantly washing their hands, consuming almost an entire bar of soap in the day, can you accept that less frequent soapy-hand-washing is actually sufficient, in an intellectual sense. If that less frequent soapy-hand-washing is sufficient from a statistical/medicinal perspective, then another valuable question might be whether the continuous no-soap washing is sufficient to assuage your OCD from your intuitive sense of germs. You may do the cost/benefit and find that it's actually a great trade to use no-soap most of the time, and – Cort Ammon Jan 09 '16 at 01:48
  • soap only some of the time (which does the real hand cleaning). – Cort Ammon Jan 09 '16 at 01:49
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    @ZachMierzejewski ... really? I'm not a participant on Skeptics, but it seems to me that you and your upvoters are setting the bar for "notable" absurdly high. The belief that soap serves a hygiene purpose is clearly held by most people, since almost everyone (at the *very least* in the west) uses it whenever they wash their hands. If this were false, it would mean that the entire soap industry is based upon nothing but pseudoscience and fraud. If a belief which is held by most human beings and sustains a multi-billion dollar industry isn't "notable", then what is? – Mark Amery Jan 09 '16 at 11:03
  • @ZachMierzejewski it might not be a "notable claim" that soap is *ineffective* but it is basically the same as asking "is soap effective"? And that is surely a notable claim per the definition in your link. – Martin Smith Jan 10 '16 at 15:38

3 Answers3

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Washing your hands with plain water of a normal temperature is significantly less able to effectively sanitise against bacteria, viruses, and many protozoa. The oil on your skin will hold pathogens pretty effectively. The detergent in the soap helps to break down the cell walls in some types of prokaryotes (bacteria) and eukaryotes (other living microbes) and also to remove the oil so that virus particles can be removed in sufficient numbers. Different soaps and detergents will have varying levels of effectiveness. The CDC provides quite a bit of information about sanitisation. This page explains how to wash your hands effectively to remove pathogens.

Here is a quote from a study specifically comparing hand washing with and without soap:

Handwashing with water alone reduced the presence of bacteria to 23% ... Handwashing with plain soap and water reduced the presence of bacteria to 8% ... The effect did not appear to depend on the bacteria species (PubMed 21318017).

The above results may or may not be similar to those for viruses or protozoa. Also, the amount and type of oil on the skin before washing probably plays a large role, as probably does the method and material used to dry the skin. Different situations call for different approaches and levels of sanitation.

Interestingly, the same study mentioned that no specific instructions were given for the washing technique, other than using a paper towel to dry:

Participants assigned to handwashing were asked to wash their hands as they would normally do, without instructions on length of time or thoroughness. The volunteers allocated to handwashing were then provided with a paper towel to dry their hands ... Participants took on average 12 seconds to wash their hands with water alone, and 14 seconds to wash their hands with water and soap (PMC3037063).

Michael
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  • Good, short and on-point. – Haider Jan 07 '16 at 09:27
  • Does this imply that if soap is not available (say, while camping or in the army, or even in a public restroom) then washing with only water is a waste of water? – dotancohen Jan 07 '16 at 10:57
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    Yes, due to such ambiguities, I was reluctant to mark this as the best accepted answer. If no one can provide a better one then, inevitable this will be the one that'd be marked as accepted. Personally, I think washing hands does help to some extent because back then [ Approximately a century ago ] there was no soap and people had to rely on a hand wash using water. At least, they survived. – Haider Jan 07 '16 at 11:24
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    The thing about pathogens is that you can rarely eliminate them all. The better you wash, the less remain. How clean is necessary depends on all sorts of factors, such as what pathogens are around, how strong the participants' immune systems are, and what is being done with the hands. One level of sanitation is not appropriate to all cases and all people. Some pathogens (such as common bacteria) take a large number to cause infection while others (such as HIV) take much less. At the same time, different pathogens infect different types of human cells (different tissues). – Michael Jan 07 '16 at 11:45
  • For example, the common cold infects cells in the respiratory tract. Hence, this pathogen must come into contact with those cells to cause the cold. On the other hand, HIV infects certain white blood cells, so contracting HIV would require that this pathogen contact those particular white blood cells that it infects. Generally speaking, a virus must come into contact with its particular type of host cells to infect. Bacteria are a little bit different, but they still follow a similar pattern where certain areas are their desired breeding grounds. – Michael Jan 07 '16 at 11:54
  • Water does some good. Prolonged water plus rubbing etc does more good. Soap does more again. A bar a day is excessive to achieve what you want. Try this on hair first with shampoo. Then on hands with soap where it is less obvious. Note how much shampoo it takes to clean your hair moderately well typically with ONE shampoo application. Then - next time hair needs shampooing: (1) Wash hair withy just enough shampoo to give a very very minor lather- maybe 5% or normal or less. Run in wellish - say 30 seconds and rinse wellish. (2) repeat also with v small amount of shampoo. ... – Russell McMahon Jan 07 '16 at 12:11
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    ... (3) 3rd time - say 5% usual shampoo. You should usually get and excellent lather and clean hair. || Now try that with soap on hands. Just a wipe across soap surface with wet hands or even dry hands on wet soap. Only a minor trace needed. Rub well and repeat and repeat. Wow. || Look at Lauryl dimethyl benalkonium chloride. (Various names - quaternary ammonium salts etc). Look up cleaning stats. Look at affect of residual and how long it lasts. Note that you can use 0.1% or even 0.01% solutions and get effectiveness. Note that the above rerewash system allows IMMENSE efficacy with .... – Russell McMahon Jan 07 '16 at 12:14
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    ... very very dilute solutions and minimal amounts of product. || Realise that it's an obsession (we all have them somewhere) AND that in fact killing off more than major germs is WORSE for your health long term. Learn that living with SOME germ is better for you. Now convince yourself of what you now know to be true. That's the hard part :-). Enjoy. – Russell McMahon Jan 07 '16 at 12:17
  • Given 23% and 8% figures: So a good water only handwash x 2 with rpoper care can be expected to give 8% x 8% = 0.64% of original . And a 3rd takes you to around 0.05% of original or 2000 x reduction. That may be pushing things, but a full and proper wash procedure repeated a few times with water alone should be "extremely effective":. No? – Russell McMahon Jan 07 '16 at 12:21
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    @RussellMcMahon -- Perhaps, but it may not work linearly. The drying procedure is probably important as well since the scrubbing involved can take off some oil pretty effectively, depending on the materials and methods used. Soap can get into small crevices that a towel cannot, but rubbing can remove skin cells, along with whatever is on the skin. Also, one would need to read the details of that study to see the methods used in both groups. – Michael Jan 07 '16 at 12:28
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    -1. From my experience with Gram-positive bacteria and yeast, detergent alone (such as 10% SDS) does **not** break down their cell walls. Also, the question asked whether washing hands with plain water removes germs, and the source cited states that it did in fact remove 77% of germs. – March Ho Jan 07 '16 at 12:43
  • @MarchHo -- There is a good chance that much of the removal was from the drying process used. A good scrubbing after washing with plain water could remove a lot of oil and other substances from the hands. Also, longer exposure to the water would naturally remove more. Soap expedites the cleansing process, making a large removal more practical with less scrubbing and probably in less time. – Michael Jan 07 '16 at 12:49
  • @Haider A century ago, the death rate from infectious disease was more than ten times what it is today. Most of the decline probably can't be attributed to non-medical-professionals washing their hands... but if you're looking for evidence of sufficient handwashing, the lepers and plague victims of 1916 don't make for good role models. – Sneftel Jan 07 '16 at 13:10
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    @Haider: Soap was there [all the way back to the Sumerians](https://en.wikipedia.org/wiki/Soap#History_of_cleansing_soaps). It's the knowledge of what actually *causes* illness, infection etc. that made people *use* soap -- in the appropriate amount, and at the appropriate time -- to reduce mortality. Proper food, availability of medical aid etc. all contributed to that development. The obsession with sterility in everyday environments is a rather recent occurrence, and actually detrimental to overall population health (as opposed to sterility in, say, hospitals). – DevSolar Jan 07 '16 at 15:39
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    *"Washing your hands with plain water of a normal temperature is significantly less able to effectively sanitise against bacteria, viruses, and many protozoa."* According to your citation, the difference is only 15%, and that after hand washing removes 77% of germs. Your overall post appears to suggest that hand washing without soap is a waste, when in reality hand washing without soap still results in removing over 3/4 of the bacteria on the hands. Done repeatedly throughout the day would result in cleaner hands than someone who *infrequently* washes *with* soap. – Adam Davis Jan 07 '16 at 16:26
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    @AdamDavis -- To be honest, my real concern is that someone is going to misinterpret the results as meaning that merely getting your hands wet and then wiping them on a towel is sufficient. The nice thing about the recommendation of using soap is that it gives a much better chance that a layman will have clean hands after washing since few people would rinse so poorly as to leave soap on their hands. Rinsing with water alone is often good if you do it with care, but not everyone does. – Michael Jan 07 '16 at 16:36
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    @Michael So you are intentionally representing the data in a manner that will encourage a specific outcome not supported by the data? – Adam Davis Jan 07 '16 at 16:39
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    @AdamDavis -- I did not read the full article -- only the abstract. For all I know, the participants were instructed in a very specific manner as to how to properly wash with plain water. If someone could bring in the specific details and really explain it, that could be nice. I was trying to keep my post quick and to-the-point. There is often a sacrifice in brevity. – Michael Jan 07 '16 at 16:42
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Washing your hands with plain water does reduce germs.

It just does not remove as many of them as using soap would.

Source: Same link as Michael, and sorry for the hijack -- I know this to be true from University (where I studied Biology), but could not have come up with an English language source ad-hoc.

Handwashing with water alone reduced the presence of bacteria to 23% (p < 0.001). Handwashing with plain soap and water reduced the presence of bacteria to 8% (comparison of both handwashing arms: p < 0.001).

So, if...

  • you are rationally able to tell the difference between objects that could realistically carry a significant load of pathogens and objects that should not, and

  • washing with water alone after touching the latter allows you to

    • get around your phobia / OCD, and
    • reduces washing-induced skin problems for you,

...then by all means do wash with water alone if there is no rational reason to strive for more sterility.

That being said, and to avoid being misunderstood, after handling the former group of objects (toilet, pets, trash, ...) or before handling food, everybody should wash hands with soap, obviously.

DevSolar
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    To the anonymous downvoter: Note that I am answering somebody *admitting* to being driven by phobic behaviour, not by facing an actual health hazard. That makes for a *very* different recommendation. Do I tell my son to use soap after visiting the toilet? Of course I do. Do I wash my hands with soap before preparing food? Of course I do. Do I tell somebody that washing with water only, after touching something *in his own house*, which is probably *much* cleaner than the average house given his condition? So he might be able to stop damaging his hands by excessive washing? Of course I do. – DevSolar Jan 07 '16 at 15:31
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    You may also have received a downvote because your answer does not cite any sources or papers. Unlike other sites, that is a requirement here. – JasonR Jan 07 '16 at 15:45
  • @user19555: Sorry, I did not really pay attention which of the SE sites I was posting to. Hijacked Michael's link, because it's a) readily available and b) supporting my point as well as his. ;-) – DevSolar Jan 07 '16 at 15:53
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    No worries on the hijack. What is most important is that people get their answers, especially when the topic relates to health. – Michael Jan 07 '16 at 16:31
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    I was the (a?) downvoter, and @user19555 got it right - I was more concerned by the lack of sourced info rather than your tone or the angle you chose to address the question. Now that you've expanded your answer, the downvote has been duly changed to an upvote! – BiscuitBaker Jan 08 '16 at 08:58
  • I admire, how you actually addressed the question along with your concern for my redundant repetitive behavior. Much appreciated! – Haider Jan 08 '16 at 11:36
  • @Haider: Working with the benefit of *knowing* somebody, personally, suffering from similar OCD, and having a mild phobia myself (needles). – DevSolar Jan 08 '16 at 11:40
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If one would move his hands while washing hands with raw water, would that help in getting rid of bacteria and germs?

Yes. In fact it can reduce the bacteria on your hands by 77%. This is a significant decrease in bacteria and other contaminants. The primary action responsible for this is the mechanical scrubbing, along with the flowing water to carry away loosened dirt and contaminants.

If so, then why need for a soap?

Soap improves the action of hand washing. Soap and water together with the mechanical action of rubbing reduce the bacteria by 92%.

So soap adds an additional 15% improvement over hand washing with water alone.

Handwashing with water alone reduced the presence of bacteria to 23%. Handwashing with plain soap and water reduced the presence of bacteria to 8%. (source)

Adam Davis
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    Notes: 1) Yes, the link is the same as used in two other answers, but this one attempts to more directly answer the questions asked, rather than simply presenting the data without application. 2) This is not a medical site, and without specific references or studies suggestions as to what actions you should take are not suitable for this site, so I won't address the implied question as to whether you should or should not reduce your soap usage. – Adam Davis Jan 07 '16 at 16:16
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    Going from 23% to 8% is a 65% reduction, not 15%. That is, adding soap removes 2/3rds of the pathogens which would be left by using water alone. – Ben Voigt Jan 07 '16 at 19:50
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    I worded my post very carefully. If I wanted to make your point, I would use different words. Consider adding a post of your own, but comments are not a good place to get into a discussion about the relative merits of these two perspectives. – Adam Davis Jan 07 '16 at 19:55
  • (Or is it 92% ÷ 77% = 19% improvement?) – Ry- Jan 09 '16 at 07:03