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Why Do We Use Soap To Remove Germs And Bacteria? What Does It Do?


anopsology

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I'm in the shower using soap under my arm pits lol... Im thinking why do I do this?  Why don't we just use plain water?


Why do I have to use soap to smell good?  How does soap remove odors? I know that can remove oils from your


body.  Are the oils what make you smell?


 


Then again washing my hands.  What does soap do to remove bacteria and germs that plain water doesn't?


Is it necessary to always use soap to wash my hands?  Blah blah blah..


 


Sorry for a stupid question and wasting your time... But again Im basically wondering what soap does to make us smell better


and what it does to remove germs and bacteria than just plain water doesn't do.


 


 


 


I hope this is the right subforum for my question.  again sorry if its not


Edited by anopsology
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I'm in the shower using soap under my arm pits lol... Im thinking why do I do this?  Why don't we just use plain water?

Why do I have to use soap to smell good?  How does soap remove odors? I know that can remove oils from your

body.  Are the oils what make you smell?

 

Then again washing my hands.  What does soap do to remove bacteria and germs that plain water doesn't?

Is it necessary to always use soap to wash my hands?  Blah blah blah..

 

Sorry for a stupid question and wasting your time... But again Im basically wondering what soap does to make us smell better

and what it does to remove germs and bacteria than just plain water doesn't do.

 

 

 

I hope this is the right subforum for my question.  again sorry if its not

 

I've had a look on the web about this and I must say I don't think it is a stupid question at all. It seems quite a complex issue.

 

Soaps will tend to disrupt the bilipid layer that forms cell membranes, so it will tend to inhibit bacteria, but apparently there can be significant populations of bacteria in soap itself nonetheless. 

 

Your skin secretes oils and fatty acids, some of which can interact with bacteria to produce body odour. Getting rid of this accumulated layer of degraded oils periodically will reduce any smell. But it seems to be quite complicated: in part you smell according to what you eat, as some of the substances in your food or their metabolic byproducts are secreted through the skin. (Perhaps this explains the well-known phenomenon by which different women find different perfumes work best for them. I had one girlfriend who smelt absolutely gorgeous with Rive Gauche, whereas the woman I eventually married smelt best with Calandre) More here: https://en.wikipedia.org/wiki/Body_odor

 

My grandfather used to use sharp sand and cold water for washing his hands after he had been working in the garden. That certainly was a good way of getting rid of the soil, presumably because it had an abrasive action, rather like a scrubbing brush. So there are alternatives to soap, for some purposes at least. But garden soil has no oily components so it works for that, whereas any dirt with an oily of fatty component will need soap or other detergent to remove it. 

Edited by exchemist
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I've had a look on the web about this and I must say I don't think it is a stupid question at all. It seems quite a complex issue.

 

Soaps will tend to disrupt the bilipid layer that forms cell membranes, so it will tend to inhibit bacteria, but apparently there can be significant populations of bacteria in soap itself nonetheless. 

 

Your skin secretes oils and fatty acids, some of which can interact with bacteria to produce body odour. Getting rid of this accumulated layer of degraded oils periodically will reduce any smell. But it seems to be quite complicated: in part you smell according to what you eat, as some of the substances in your food or their metabolic byproducts are secreted through the skin. (Perhaps this explains the well-known phenomenon by which different women find different perfumes work best for them. I had one girlfriend who smelt absolutely gorgeous with Rive Gauche, whereas the woman I eventually married smelt best with Calandre) More here: https://en.wikipedia.org/wiki/Body_odor

 

My grandfather used to use sharp sand and cold water for washing his hands after he had been working in the garden. That certainly was a good way of getting rid of the soil, presumably because it had an abrasive action, rather like a scrubbing brush. So there are alternatives to soap, for some purposes at least. But garden soil has no oily components so it works for that, whereas any dirt with an oily of fatty component will need soap or other detergent to remove it. 

 

 

are the bacteria, germs and odors trapped within the oils?  and using soap removes the oils which allows the bacteria and what not to be washed away easier?

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are the bacteria, germs and odors trapped within the oils?  and using soap removes the oils which allows the bacteria and what not to be washed away easier?

I'm not really sure, but I suppose that, as your skin acquires a layer of oily secretions during the day, it seems reasonable that the bacteria and fungi etc will be in or on that layer and so removing that layer will get rid of them. 

 

But it seems that soap's ability to disrupt the cell membranes of bacteria, and thereby kill them directly, is also important.

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  • 4 weeks later...

are the bacteria, germs and odors trapped within the oils?  and using soap removes the oils which allows the bacteria and what not to be washed away easier?

 

Yes.

 

Soaps are comprised of a molecule called a surfactant which has two components: a detergent and an emulsifier. Detergents tear things apart, while emulsifiers gather things into globs and surround them.

 

Soap molecules have a water-loving end and a lipid-loving end. The lipid-loving end of the molecule attaches itself to any fats it finds on dish or skin, and the water-loving end can then be attacked by water. (Hot water has enough kinetic energy to drag the molecules and their captive fats away from the dish/skin.)

 

More soap molecules can now surround the rest of the fatty bit (called emulsification) leaving the fat on the inside, where it cannot re-attach to anything. It can then be carried away by the water.

 

Note that soap does not kill bacteria (unless it has an added disinfectant). The process of washing with soap simply facilitates the mechanical removal of bacteria.

 

 

 

http://www.planet-science.com/categories/under-11s/chemistry-chaos/2011/06/soap---how-does-it-get-things-clean.aspx

Edited by DaveC426913
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But it seems that soap's ability to disrupt the cell membranes of bacteria, and thereby kill them directly, is also important.

 

I missed this before. I'm finding conflicting info on it. One site says:

 

  • Regular soap won’t kill healthy bacteria on the skin’s surface.

and yet in the same breath:

  • People may not wash hands thoroughly enough for regular soap to kill bad bacteria.

https://www.unitypoint.org/blankchildrens/article.aspx?id=68ac1797-834f-409c-947b-4df322b04380

 

 

Regular household soap or cleanser does not kill germs ... rather, it suspends (or lifts) them off the skin surface, allowing the microbes and soil bits to be rinsed down the drain.

http://www.goaskalice.columbia.edu/answered-questions/does-soap-kill-germs-0

 

 

Not exactly scholarly sources, but still, most layperson's wisdom suggests soap does not kill bacteria. It would be interesting to see something more trustworthy.

Edited by DaveC426913
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I missed this before. I'm finding conflicting info on it. One site says:

 

  • Regular soap won’t kill healthy bacteria on the skin’s surface.

and yet in the same breath:

  • People may not wash hands thoroughly enough for regular soap to kill bad bacteria.

https://www.unitypoint.org/blankchildrens/article.aspx?id=68ac1797-834f-409c-947b-4df322b04380

 

 

Regular household soap or cleanser does not kill germs ... rather, it suspends (or lifts) them off the skin surface, allowing the microbes and soil bits to be rinsed down the drain.

http://www.goaskalice.columbia.edu/answered-questions/does-soap-kill-germs-0

 

 

Not exactly scholarly sources, but still, most layperson's wisdom suggests soap does not kill bacteria. It would be interesting to see something more trustworthy.

My understanding is that soaps can disrupt the cell bilipid layer but it depends on the organism. But I can't recall where I read that. 

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The answer has already been provided.  Soap works because it binds with both water soluble molecules and oil soluble molecules.  You can test this.  Take a bowl containing a small amount of water and add a few drops of cooking oil.  The two don't mix.  Now, add some soap and agitate.

 

When you sweat, you are exuding both salty water and oils.  Soap facilitates the removal of both of these to prevent the growth of bacteria that contributes to "stink"

Regular soap doesn't kill bacteria because it isn't antibacterial.  Anti-bacterial soap isn't at all necessary, and instead contributes to the evolution of anti-bacterial resistant strains of bacteria.  Washing with soap is a physical removal of contaminants from your skin, and if you are doing it correctly, you don't need anti-bacterial additives in your soap.  If you aren't doing it correctly, as most people don't, then the addition of anti-bacterial elements in the soap won't help.  But none of this is important as the stink isn't the thing that is communicable, nor is the bacteria that causes stink.  The thing to be avoided is communicable diseases, and the proper use of soap physically removes these microbes.  The way I have taught my nieces to wash their hands is to recite the alphabet while they aggressively rub their fingers.

 

It is important to clean the areas that come in contact with the mucus membranes of your body.  Unless you have a cut, your skin is pretty good at keeping out microorganisms outside of these areas.  The mucus membranes that we are talking about are in the nose, mouth, eyes, and genitals.  Washing your hands prevents the transmission of harmful microbes to these areas.  Soap is a mechanical method of removing these microbes from your hands, because you can't be reasonably required to stop touching your face.

Edited by JMJones0424
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  • 2 weeks later...

The answer has already been provided.  Soap works because it binds with both water soluble molecules and oil soluble molecules.  You can test this.  Take a bowl containing a small amount of water and add a few drops of cooking oil.  The two don't mix.  Now, add some soap and agitate.

 

When you sweat, you are exuding both salty water and oils.  Soap facilitates the removal of both of these to prevent the growth of bacteria that contributes to "stink"

Regular soap doesn't kill bacteria because it isn't antibacterial.  Anti-bacterial soap isn't at all necessary, and instead contributes to the evolution of anti-bacterial resistant strains of bacteria.  Washing with soap is a physical removal of contaminants from your skin, and if you are doing it correctly, you don't need anti-bacterial additives in your soap.  If you aren't doing it correctly, as most people don't, then the addition of anti-bacterial elements in the soap won't help.  But none of this is important as the stink isn't the thing that is communicable, nor is the bacteria that causes stink.  The thing to be avoided is communicable diseases, and the proper use of soap physically removes these microbes.  The way I have taught my nieces to wash their hands is to recite the alphabet while they aggressively rub their fingers.

 

It is important to clean the areas that come in contact with the mucus membranes of your body.  Unless you have a cut, your skin is pretty good at keeping out microorganisms outside of these areas.  The mucus membranes that we are talking about are in the nose, mouth, eyes, and genitals.  Washing your hands prevents the transmission of harmful microbes to these areas.  Soap is a mechanical method of removing these microbes from your hands, because you can't be reasonably required to stop touching your face.

 

 

 

 

Thanks just saw this.  The friends i live with were debating  with me that when washing our hands plain water and rubbing is just as good at removing germs and bacteria as washing with soap

 

I needed some science to show them why it wasnt true.

 

If I was too explain this in the simplest way.. It would again be .......   Soap helps remove the oils on your hands and the bacteria or "germs"  are stuck on the oils?

Edited by anopsology
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Yes.

 

Soaps are comprised of a molecule called a surfactant which has two components: a detergent and an emulsifier. Detergents tear things apart, while emulsifiers gather things into globs and surround them.

 

Soap molecules have a water-loving end and a lipid-loving end. The lipid-loving end of the molecule attaches itself to any fats it finds on dish or skin, and the water-loving end can then be attacked by water. (Hot water has enough kinetic energy to drag the molecules and their captive fats away from the dish/skin.)

 

More soap molecules can now surround the rest of the fatty bit (called emulsification) leaving the fat on the inside, where it cannot re-attach to anything. It can then be carried away by the water.

 

Note that soap does not kill bacteria (unless it has an added disinfectant). The process of washing with soap simply facilitates the mechanical removal of bacteria.

 

 

 

http://www.planet-science.com/categories/under-11s/chemistry-chaos/2011/06/soap---how-does-it-get-things-clean.aspx

 

 

thank you sir

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If I was too explain this in the simplest way.. It would again be .......   Soap helps remove the oils on your hands and the bacteria or "germs"  are stuck on the oils?

No.  Only water soluble molecules can be removed with water.  Coat your hands in an oil and then try to wash with only water, it won't work.  Soap is beneficial because it binds to both oils and water, and so when you wash your hands with soap, you remove both water soluble and oil soluble molecules.

 

I wouldn't recommend it, in fact I'd highly recommend against it, but my grandfather used to use gasoline to wash his hands to remove oil.  In this case, he was removing oil soluble molecules without removing water soluble molecules.  He'd then use soap and water to clean the gasoline off of his hands.

 

Bad microorganisms may be water soluble or oil soluble.  Soap allows the removal of both regardless of the solvent.  Water without soap only removes one.  Gasoline without soap only removes the other.

 

In the simplest way, soap allows the mechanical removal of oil soluble and water soluble compounds by rinsing with water.

Edited by JMJones0424
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I wouldn't recommend it, in fact I'd highly recommend against it, but my grandfather used to use gasoline to wash his hands to remove oil.  In this case, he was removing oil soluble molecules without removing water soluble molecules.  He'd then use soap and water to clean the gasoline off of his hands.

 

 

Ah, the "good old days"!  I remember when I was young we had a "degreaser" soap that we got from the John Deere dealer that smelled like fuel, and I think they had to stop selling it in the 1990s , for some reason, lol .  Sawdust and dry sand can be effective at removing oil and grease from hands, and I have done so many times.  

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