Why Soap Works

Mar 13, 2020 · 131 comments
Neha Sangoi (Dallas Texas)
No need to share my thoughts just wanted to let you know the credit for jalapeño quote at the end might belong elsewhere https://patch.com/texas/round-rock/texas-city-devises-novel-way-toward-coronavirus-prevention
Robert Monteverde (Pittsburgh)
I agree with all of these statements but there is no mention of the dark side to frequently washing your hands. I have been a nurse for 39 years. The top layer of skin on my hands no longer grows secondary to the chemical onslaught of the vigorous cleansing. It has been very frustrating because hand moisturizers , including Vaseline no longer make a difference. I know that I am not the only one with this issue
Jibber Jabber (Liverpool, UK)
@Robert Monteverde What you are describing is cumulative damage caused over many years. For the purpose of combating the Coronavirus, one of the most effective measures is washing of hands regularly with soap and water. People should not be put off from doing this.
beatgirl99 (Pelham Manor, NY)
This may sound stupid, really stupid, but here goes anyway. If soap disrupts and destroys the virus, could those same properties be used within the body to prevent them from multiplying? I don't think soap is toxic. There are some really smart people commenting here, I wonder if anyone knows? Thank you.
Giskander (Grosse Pointe, Mich.)
While its not a perfect remedy for theridding the filth brnrsth the fingernails, a good hand brush is a good start. Unfortunately, they're hard to find, I've been using one brought home from a hospital years ago.
margaret soltan (washington dc)
Safeguard, thy beauty is to me Like those Nicean barks of yore, That gently, o'er a lathered sea, The worried-well hygienic bore To their own healthy shore. When quarantined I feel a rale Thy hybrid structure virus shreds. Thy micelle bubbles now we hail: Thy hydrophilic head And thy hydrophobic tail.
Michele (Cleveland OH)
I was struck by the illustration. Take that filthy watch off before you wash! Don’t undo all the good of hand-washing by immediately touching a contaminated object.
David Pasquariello (Rhode Island, USA)
True patriots wash their hands, especially after using a restroom!
Larry M (Minnesota)
Excellent. Shared with my co-workers.
Meredith (Wilmington, NC)
Great article on the “why”. Honestly if I understand why I’m doing something, I’m much more likely to do it. I do have a couple of questions though. Are all soaps created equal? What about antibacterial soaps vs regular soaps? I would love to see this become a series of articles, maybe ending with some DIY recipes for how to make your own.
Barry (Stone Mountain)
Here is what I carry in my car if I am out of hand sanitizer. Wet a paper towel and add some soap to it. Then fold towel into plastic sandwich bag. Use it to clean hands after being out to stores, etc.
Katherine (Conway, MA)
Is using detergents such as dish washing liquid as effective as washing with a bar of soap?
Wise12 (USA)
A lot of people think soap just washes away the organisms. This article is good stuff.
Dee (Anchorage, AK)
When I run out of alcohol wipes can I use soap and water to deactivate the virus on surfaces?
Aguadejamaica (Katy, TX)
Excellent informative article!!!! During my formative college days I learned how washing your hands prevents getting diseases. I passed this information to my husband and children. They all made fun of me every time we went to a public restroom when I stressed the importance of not touching the faucet and door after washing their hands, using the paper towel or elbows and keeping their hands up. To date, they look at me and say: I know, I know, like a surgeon... I shared this article with them and got a call from my youngest telling me “Mom you were right!”. Priceless... (big grin on my face).
PJ (Alabama)
Friction and flow is what they taught me in nursing school. Rubbing all over your hands under running water is the most effective action. Soap (and it does NOT have to be “antibacterial”) helps. Just wash your hands.
James Chan (Philadelphia)
The graphic by Corum and Jabr is divine. Great reporting. Bravo,
Diane Joss (Scottsdale, AZ)
Hand-washing techniques: Don't rush, wash backs of hands and wrists, not just palms, go between fingers with opposite hand, rub around fingernails (cuticles), rinse thoroughly, I use hot water and also cold water to finish - some bacteria are more easily eradicated at various temperatures.
Janet (Los Angeles)
Great article which explains so much about the impact of hand washing and soap, Thank you! It will make me more mindful when washing up,
Jeffrey Freedman (New York)
"Why Soap Works" is such a wonderful article for many reasons. I think most people's fears since the Covid-19 pandemic relate to a feeling of not being able to control a threat- Ferris Jabr's piece reminds us of something that can be done by each person. Also, the illustrations of how soap works are an enjoyable way to learn for both young and old. They got me to look again at a book on my shelf, Morrison and Boyd's "Organic Chemistry," which was a classic text for premedical students. From my 1973 edition: "The making of soap is one of the oldest of chemical syntheses. (It is not nearly as old, of course, as the production of ethyl alcohol; man's desire for cleanliness is much newer than his desire for intoxication.)"
Dr. JMD (New Jersey)
Excellent article! Soap may well have saved more lives in the last 150 years than all the antibiotics, surgical interventions and other medications combined. And now, in the absence of a vaccine, it may also save us from COVID-19, so lather up!
Janet Hong (Chicago)
Thank you so much for this exceptionally well-written article. I had actually thought experts were offering hand-washing mostly as something generally good to do, in the face of so much that’s out of our control. I didn’t know what was going on at the molecular level when soap encounters a coronavirus’ fatty exterior. I wish everyone in the world could read this article— it really convinces you to wash your hands frequently, and for that 20-second length of time!
Enlynn Rock (Winchester)
A gardener friend of mine always scraped her nails across a bar of soap when she was going to be digging. The soap filled most of the space under the nail and kept the soil mostly out. Scrubbed out with a nail brush when finished. This might work for some other tasks too.
Gretchen (Minneapolis)
While using soap is the best way to clean oneself, my question is this: Are all soaps created equal? What ingredients in soap make this work? Do glycerin soaps clean as effectively as lye soaps?
Cagatay (Istanbul)
It is important to learn how smth works to use it effectively. One important thing That I learned is that I need to apply the soap thoroughly with very llittle and then and only then put my hand under the water to rinse the soap and residues of lipid coated bacteria and viruses. Putting your hand under the water during soaping may not be as effective, the soap will be drained before doing its job.
Jane K (Northern California)
Working for a for profit hospital, our annual education informed us that alcohol based sanitizers were more effective than soap and water. I’ve never really liked them much, and preferred to wash my hands. It’s easier on my skin and doesn’t leave a weird residue. This article just confirms that I’d still rather wash than use the alcohol.
Adrien (Australia)
@Jane K Interesting they told you that. Does this mean that the surgeons there use sanitizer rather than scrubbing up before surgery?
Karen Green (Out West)
Sanitizers are more expensive than soap. Again, profit above all.
RN (PA)
After using hand sanitizer from the dispenser just outside of a patients room, i wash my hands with soap and water at the sink inside the room. I cannot skip the hand sanitizer because the hospital designates certain staff as secret watchers. They take note if you don't use the hand sanitizer from their hallway vantage point, but do not see when you go in to the room and wash your hands thoroughly at the sink before approaching the patient. I much prefer washing with soap and water so will do both.
Susan L. Paul (Asheville, NC)
@RN What a horrible system they have set up... to have nurses spying on other nurses.! Get a different job! And continue washing your hands. A retired BSRN
Jane K (Northern California)
Same here, @RN.
JenD (NJ)
The explanation in this article is why I more or less shrug when I see people hoarding hand sanitizer. Good old soap and water will do the job nicely!
Adrien (Australia)
@JenD Absolutely but sometimes you do not have access when you are out and about
L Martin (BC)
A pitch perfect "soap" opera we all need to hear,
brettze (Antioch , CA)
I wonder if women who are heavy users of hand lotions to keep their hands soft and sexy are less likely to use soap as often as should because this would mean another application of hand lotion afterwards. I don't know of any anti bacterial or anti viral hand lotions around if any for those women who are not as clean as should.. I hope I am not starting a flaming ..
JAR (North Carolina)
I can't wait until Mr. Jabr is inundated will bad reviews by the anti-soapers. Like the anti-vaxxers, they don't believe in science. This hydrophilic and hydrophobic stuff is not proven.
Anna (Sonoma)
Great informative interesting article. May I add an element to the hand washing discussion I haven't yet seen addressed? Look at the palms of your hands... then check if you can see the underside of your nails extending past the tips of your fingers. If you can see your fingernails extending past your fingertips you have what is called the subungual region, a significant site for harbouring pathogens, parasites and viruses. Scientific research has discovered this space creates a perfect environment for proliferation of these minute lifeforms, due to the porous nature of the nail underside. After testing of volunteers' and medical personals hands, the hands themselves were home to hundreds of bacteria, while the subungual areas yielded hundreds of thousands of bacteria per fingertip. The fingernails harboured the same types of bacteria as the rest of the hand, just a lot more of them. The scary part is, the space under your nails, due to the moist porous nature, is almost completely impervious to the best and simplest means we have of spreading disease, hand washing. Can a world where the fashion styling of painted, decorated, long, kind of long, and super long fingernails exist as almost ubiquitous, alongside a world of highly contagious pandemic type diseases? How can we continue to look upon a set of long fingernails, fake or natural, as anything other than walking petri dishes. Kardashian women and global citizens...can we all just clip our dang fingernails?
ms (ca)
@Anna This is why some healthcare workplaces do not allow people to paint their fingernails or grow them long or wear nail extensions. As a healthcare professional who also plays instruments, I keep my nails clipped and undecorated.
Kris (NJ)
@Anna My nails just about reach the tip of my fingers During the process of cleaning my hands I often use the nails on one hand to scrape under the nails of the other and allow the soap to access the deeper reaches. This leaves them very clean and just may be equal to a very short nail that would require a hand brush to get under the stub.
Mark (San Francisco)
Really great explanation. I shared with my 75 neighbors ( we live in the hills south of San Francisco) and my house cleaners! Typical well done and informative NYT reporting.
David (San Diego, CA)
Yea for soap! I make my own, you should too! It's a fairly easy and practical activity, with many rewards. Lots of resources on the internet. My favorite is a combination of just a few simple vegetable oils and a little fragrance. Next time you're in the store, check out the ingredients on your favorite bar soap. Mine had cornstarch as its second most common ingredient. Cornstarch in soap makes as much sense as sawdust in bread. Learn to make your own and you'll never go back.
rubyp3 (pittsburgh pa)
Thank you for the illustrations! Great to explain to the kids with the visual
Robert Hunt (Vermont)
If people were to rely on soap and water over the excessive use of hand sanitizers, it might reduce the proliferation of superbugs.
Laurie Menéndez (Toronto, ON)
Many thanks for the science-based article. Is there any research available that has identified which intracellular amino acids COVID-19 utilizes to replicate?
Dan Millward (Boise, ID)
The efficacy of soap or any other surfactant molecule as a means of public health is almost certainly primarily due to its physical removal of microbes from our hands and not to a spontaneous disruption of the lipid bilayer (which is essentially self-assembled surfactant molecules) around the coronavirus, or other enveloped viruses, or in bacteria. That is not to say that this disruption does not occur, but the cells on our hands are also surrounded by phospholipid bilayers. It is statistically FAR more likely for a given soap molecule to diffuse into one of our skin cells lipid bilayer than into a virus or bacteria present on our hands. Moreover, the time scale of diffusion is slower than one might expect, I wouldn't count on instantaneous virus rupture (or even within the span of the happy birthday song). It's far more likely that soap is dispersing the aerosolized mucus (through the micelle mechanism) that the virus particles is encased in, thus facilitating the water to wash the virus away. That's my two cents as a Ph.D. chemist with a long interest in self-assembly.
Humanist (AK)
@Dan Millward And this would also explain the fact that intact viruses have been detected on bar soap after its use for hand washing. If soap was as good at breaking the lipid sheath as described in this article, surely wet soap would quickly do the same thing. Rinse well, everyone!
Dialysis RN (TX)
@Dan Millward I work in healthcare, and I teach (among other things) hand washing to home dialysis patients, a population who are chronically ill, immunocompromised, and vulnerable, I emphasize RINSING well, drying well, and using a paper towel to turn off the faucet. Patients practice and I observe. Even my best patients tend not to rinse well, but it's crucial. So important, in fact, that they have to demonstrate their technique with every monthly visit, to ensure the proper technique has become a deeply ingrained habit.
Sanjay (Patel)
Why not used liquid soap instead soap bar?
MGU (Atlanta)
The association between maternal death and absence of hand washing by MDs in the 19th century — This was amplified by the practice of conducting autopsies and then going to maternity wards to deliver babies. The result was a much lower maternal death rate among women delivered at home by midwives.
tdb (Berkeley, CA)
Another question for experts. Can the virus come in through the ear canal too? In that case, can earphones and earbuds if handled with infected hands create contagion? It is all about eyes, moth and nose, not touching those hot spots, but are ears possible hot spots too and things we put in them increase risks of contagion. Or is this too far fetched? Also, if so, how do we clean them? Or simply refrain from inserting them in our ears?
djk (norfolk, va)
@tdb the ear canal is not lined with a mucus membrane, so theoretically, no.
Humanist (AK)
@tdb You do have mucous membranes in your ear, but they are in your middle ear, inside the ear drum, which creates a physical barrier between the outer and middle ear. Seems to me that if there are viruses on your earbuds, it's far easier for them to enter your body via your fingers when you handle the ear buds and then touch mucous membranes of your nose, mouth or eyes.
Jaque (California)
Wasn't wood fire ash used long before soap? In India people in villages still use ash to wash utensils etc. It contains Potassium Hydroxide.
Sanjay (Patel)
As child growing up in India ...and visiting country side during summer break...it was not uncommon to take a fistful of dirt and wash hands mixing water in absence of man made soap ..
maureen (palm desert)
I agree with the hand washing efficacy and have a question: should the drying towel be disposed or can a conventional cloth towel be reused after hand washing? In a home setting, for example.
Humanist (AK)
@maureen Probably best not to re-use unless you can disinfect it. Disinfection could be done via hot water washing (the virus cannot withstand temperatures above about 140 F for very long) or a soak in bleach solution. I am also considering using my Instant Pot as an autoclave.
Krishnan (Bangalore, India)
Excellent article prompting one to dwell deeper in to the subject of humble, taken for granted soap. Use of normal commercial soaps, skin often dries out. Your body tries to compensate for this by making more oil. In the end, it just clogs your pores, and can contribute to blemishes. If you’re already dealing with acne, this is the last thing you need. Suggest the use of soap containing Glycerin. It’s a humectant, which means it attracts moisture. Regular use of glycerin soap will draw moisture to your skin, and lock the water molecules in place. Your skin may feel moist for several hours after use. Regular use should keep the skin soft. Glycerin soap an anti-aging product, since it keeps your skin healthy, a great choice for people who have dry or sensitive skin. Since glycerin soap naturally has a low pH, the skin is able to retain its natural moisture and remain fresh throughout.
A j (Phoenix)
Thank you for this article. The graphics were so spot on too! My 9 year old was so impressed that she washed her hands very carefully this morning!
Don (Florida)
This is the first article that I have ever read that stated/explained that "regular" soap kills bacteria [as well as removing them]. The many articles I have seen, old & new, specifically state that soap does not kill bacteria. [then proceed to discuss antibacterial soap, hand sanitizers etc]. Is the information on the kill mechanism based on very recent research findings? Or why isn't this information more widely known, especially in light of the current interest in the subject?
Jeanne (Missouri)
@Don You bring up an interesting point. All cells have a lipid membrane of some sort- including our own. I imagine it has something to do with the fact that our own skin has a layer of dead, keratinized cells on top, protecting our vulnerable fresh cells from being destroyed. As for bacteria, some have a capsule surrounding them, while others don't. Maybe this is why soap can disrupt some lipid membranes of bacteria, but not others.
Counter Measures (Old Borough Park, NY)
Which soap?! Dial, Ivory, or any soap?! Come on!!!
Anth (San Diago)
@Counter Measures Any soap. Soap is soap. The only difference is marketing a packaging. The same applies to shampoo too
Tanya (Canada)
Soap. Period. Brand doesn’t matter.
Allan (Rydberg)
Soap has poor results when used on grease or oil. Try washing your hair with soap.
Diana (Germany)
@Allan Depends on the soap you use. I've been washing my face, body and hair with Aleppo soap from Syria for several years now. I have fewer problems with dry scalp and the bars of soap are environmentally friendly, no plastic container like shower gel and shampoo had.
Jay Orchard (Miami Beach)
Thanks for coming clean about how soap works. No longer any need for people to work themselves into a lather when they can't find hand sanitizers.
Bruce (NY)
This will probably cause people to hoard soap now.
Jim (California)
Mr Jabr - Why did you not summarize in simple common terms? Soaps are produced by mixing a fat (e.g. tallow, coconut oil) with a alkaline (e.g. caustic soda, lye, potassium hydroxide). The 'Liquid Soaps' , such as Soft Soap, are detergents. There area also bars made from detergents. Well formulated hand and body detergents clean as well as soaps, but due to the pH (acidity) may not have the anti-microbial effect of a bar soap.
Zetelmo (Minnesota)
Around 1961 I had a job in Hawaii with Atomic Pest Control. Every day I was working with one poison after another, and became paranoid that they were going to get me one way or another. My solution was to wash my hands at every opportunity~! I have never stopped.
JM (Western MA)
While I love bringing critical - yet simple and sometimes overlooked - practices into the open for clarity, like this article did brilliantly, I can’t help but shudder at the thought of so many folks not being aware that washing your hands should be done regularly. I’ve heard folks scoff on social media about doing it, even now! The WHO and NYT can only do so much. How do we make America more hygienic again?
Laura Lynch (Las Vegas)
Maybe push how good it feels. I feel good after taking a shower, fresh and clean. Same after washing my hands and face.
Weave77 (Ohio)
“Wash your hands like you’ve been chopping jalapeños and you need to change your contacts.” For how simple that advice is, it's surprisingly descriptive and actionable. Much more so, in my personal opinion, than "sing the ABC song twice" or other similar recommendations.
Uncle Peevish (The Other Side Of The Wall)
What about modern soaps that aren’t actually soap but powerful detergents? I don’t use supermarket soap, I go out of my way for Dr. Bronner’s pure Castile soap. You should too.
NBMaggie (Toronto Ontario)
I think the price of the much-vaunted Dr. Bonner’s product is bonkers. I’ve been using my homemade Castile soap with a bit of coconut oil added for better sudsing action ever since I started making soap about ten years ago...works well. YouTube videos showed me how simple both the process and ingredients are. Basically you carefully mix lye and water, cool it down some, add it to warm olive and coconut oil and then use a stick blender to get it to the consistency of warm pudding. Put it in a loaf pan, age it a bit, cut it into bars et voila: soap. My homemade soap recipe makes ten pounds from approximately three litres of lesser quality olive oil and a bit of lye (sodium hydroxide). I grate some of it up and dilute it with water and aloe to make liquid hand soap; I use more grated Castile and mix it with borax and sodium carbonate ( ph ) which creates a very effective laundry powder. Then there’s baking soda and vinegar for other cleaning tasks...but don’t get me started....oh, too late...sorry.
kr (nj)
Plain soap is strong enough to kill an insect. I use it instead of bug spray around my house, as it is non toxic. I have used Doctor Bronner's peppermint soap to kill aphids in the garden. If soap can kill a bug it can certainly kill a microbe.
Alison (California)
@kr Insects breathe through their skeletons. Soap smothers them.
JAL (CA)
Excellent article. As a retired chemistry teacher, I very much appreciate such a clear explanation of such a common but important product in our lives. Hurray for soap!!
EML (San Francisco, CA)
A chemist explained this to me and I thought I understood it. But your explanation and graphics did the trick. I have been washing my hands six to eight times a day. I am glad to know it serves a scientifically proven purpose. Thank you for the clarity.
Me (NJ)
@EML Six to eight times doesn't seem that often...
Lucas (Albany, NY)
Fantastic article! No bias or politics, just facts. There's an outbreak in my city and I'll be sharing this article with my co-workers and friends. Thanks!
Zetelmo (Minnesota)
@Lucas Good point~!
Jen (NYC)
I appreciate the scientific and laymen's explanations. What dismays me is that advice I thought was common knowledge must be reiterated time after time. Yet some people fail to grasp that they can control germ spreading through hygiene. At my workplace, my employer posted signs about proper handwashing. One colleague complained about it while picking his nose. I have lost hope in some people learning from our mistakes. But, after this pandemic, I'm hoping that this guidance resonates.
Allan (Rydberg)
When I was younger I would work on cars which always included grease. I noticed that when stoping for lunch i would wash with a detergent and my hands were clean. Then after returning to work they would become greasy and when i quit i would wash again and they seemed clean. The problem was after watching TV for 2 hours or so my hands would become dirty all by themselves. It was the detergent in the first hand washing that removed all the oil from my skin and left open pores. These pores became full of grease but it would not show, As time went on the grease would seep out.
Annie Sherman (Larkspur, California)
The most effective way to persuade people to do something - an easy-to-understand, scientific explanation of WHY. Bravo.
Joe (California)
I love pure factual articles like this, so helpful!!!
Chiwiz (Langdon NH)
If this is the way soap works, would it not make sense to leave a film of soap on your hands after washing? To not completely rinse the soap off???
Tanya (Canada)
Rinsing it off is key to hygienic handwashing. That’s what sends it all down the drain.
Star water (Denver)
I’ve been a soap maker for 20 years. Real soap not the detergent bars (out of an oil well) that are what the major brands sell. This is why. It works.
Hope (Washington, D.C.)
I wonder why soap doesn't also do this to your skin cells--aren't cell/plasma membranes made up of similar things?
Rick (NYC)
@Hope Your skin cells are dead at the surface.. so nothing to kill ¯\_(ツ)_/¯
Jim K (San Jose)
Here's another good idea: after you wash your hands and they are dry, apply a moisturizing cream. Skin moisturizer will leave a thin film behind that will be easily washed away, along with all of the contaminants within it, the next time you wash your hands. It creates a barrier that stops things from adhering to your skin as easily. It will also keep your skin from drying out due to the increased washing and hand sanitizer regimen. The use of a perfumed skin moisturizer can also be another constant queue that you should not be touching your face and eyes. Lastly, when washing your hands, double the period of time you normally spend rinsing them. Use very warm water.
TK (Fort Collins, CO)
@Jim K --Warm water makes no difference to cleaning effectiveness. Water temp is only for personal comfort.
MM (Irvine, CA)
Why don't we drink soapy water, then, as medicine?
thostageo (boston)
@MM maybe you can try , then get back to us
Luke (Colorado)
@MM try it out
L (NYC)
@MM: Google it.
carl bumba (mo-ozarks)
This is way overdue. Soap for hygiene is even better than aspirin is for medical treatment. It suffers the same terrible fate in our society of not being a money-maker.
Susanonymous (Midwest)
This needs to be a CDC PSA that all Americans are seeing in their social media feeds and on TV!!
BF (Upstate)
Thank you NYT. I've been googling this topic and as one can imagine, have come up with a dizzying array of contrary explanations of how soap works and, more importantly, its efficacy.
Earthling (Earth)
Thank you for posting this article!
tdb (Berkeley, CA)
Should one wash one's face with soap too once or twice a day? Will that help with viruses sticking to the face near the eyes and mouth and nose? Or should touch the face as little as possible, not even for washing?
NessaVa (Toronto)
Never thought of washing the face with soap during the day but good idea.
EML (San Francisco, CA)
@tdb I read an epidemiologist suggested we clean with soap the outer parts of our nostrils with soap and our fingers, and then snort. Never use a neti. I am going to be washing my face more thoroughly now, for sure.
SteveRR (CA)
@tdb Most viruses are picked up off of hard surfaces that you typically touch with your hands - so unless you are rolling your face on hand-rails and tabletops - no.
Duncan McTaggart (Baltimore)
Brilliant - exactly the information people need.
Maureen (Massachusetts)
This article should be front page headlines! NYT please help correct all the misinformation out there. People are freaking out about hand sanitizers when the lowly bar of soap is a more effective prevention against infection.
Retired Hard Worker (USA)
Thank you for this story. I am a science curious person, and have been wondering how soap works.
archie (St Louis)
Soap has always been my favorite “invention”, thank you so much for explaining why it works. Great article.
lwseymour (Goshen AR)
As a retired nurse practitioner and nurse educator, this is the best explanation of the mechanisms and effectiveness of plain old soap and water. Great article, wish I'd had this to give to my students when I was teaching. Should be posted everywhere!
tdb (Berkeley, CA)
Does it matter what kind of soap one uses? Liquid or bar soap? Are all based on the same "formulas"?
Natalie (Central New York)
@tdb I've been wondering this, too. What is the advantage, if any, of antibacterial soap? And is the handmade local goat milk soap that I bought at the cute little downtown shop as effective as Dial? Based on this article, I'm tempter to believe that if it lathers, it works. Those soapy bubbles are the only needed sign of effectiveness.
Juanita O (Lynn, MA)
@tdb Commercial liquid and bar soaps are both "detergents" so there are probably no differences. Try hand-made soaps available at craft shows, food coops, and organic markets - just as effective and kinder to your skin.
EML (San Francisco, CA)
@tdb I asked a chemist. She didn’t think so. They all work the same way. Their surfactants work similarly.
Per Axel (Richmond, VA)
As a OR nurse I know hand washing is very effective. We wash all the time, before very procedure, for 5 minutes. And it was a very god point that washing will kil and alow these germs to be rinsed away with water. But that alcohol works best for other germs. Now not being a chemist I would like to know the difference between a soap and a detergent. How do they work differently? Which is better for what purpose?
Nate B (Atlanta)
@Per Axel Detergent is stronger, considered too strong for delicate hands.
Zetelmo (Minnesota)
@Per Axel Why don't they add some alcohol to the soap?
Sarah Green (Calumet)
Alcohol disrupts the ability of soap to form micelles. Mixing alcohol and soap would be counterproductive.
Cousy (New England)
Young people seem to be washing their hands more than older people. My elderly mother has been pretty lax about it in general, although she is getting better now. Does anyone (scientists and medical professionals) think that less hand washing among older folks is a factor in their increased vulnerability to Covid 19?
AH (wi)
@Cousy Covid-19 is a respiratory disease affecting the lungs. Seniors, many of whom smoked for years, have weaker lungs and immune system. So they are more apt to contract covid-19 and die. Apparently it has been very rare for children (<10 years old) to be infected. Their lungs are stronger than that of an adult.
L (NYC)
@Cousy: You are confusing 2 things: risk factors and behavior. Older people are at higher risk b/c their immune systems are not as amped-up younger people's. Behaviorally, ANYONE of ANY AGE, is lowering their chances of getting infected if they wash their hands correctly. And that includes lowering their chance of getting regular flu and various bacterial infections as well.
L (NYC)
@AH: You are ignoring young people who VAPE, who have damaged their lungs very early in their lives.
M (Michigan)
Love this article. Thank You! Low tech solution with outsized impact for benefit!
Duncan McTaggart (Baltimore)
@M Low-tech is why humans exist. Too many of us now mistake commercialism for wisdom. Who was not taught to wash hands with soap by Kindergarten at latest?
Cousy (New England)
Is the temperature of the water important? I always thought that hot water was key to the effectiveness of hand washing, but I'm not seeing anything about that.
Per Axel (Richmond, VA)
@Cousy No, water temp makes no difference. As an OR nurse we wash our hands and arms up to and above out elbows for 5 minutes before every surgery.
Susan Black (Aurora OR)
I have the same question!
Duncan McTaggart (Baltimore)
@Cousy Hotter water aids the colloidal properties of the soap to remove oils. Try washing greasy dishes with hot and cold water and watch how the soap performs.
Tim Mawhinney (GA)
With store shelves now empty of hand sanitizers and isopropyl alcohol, this is a super helpful article. Thank you!
Barbara (Los Angeles)
Great article - as a scientist, I’m happy to see some sanity and responsible reporting in this frenzy over the coronavirus. It is frightening that there is so much misinformation on the internet and the average person in the US has little to no basic science education. Our national scientific institutions are under the thumbs of Trump and Pence whose only goal seems to be thwart preventive healthcare by obstruction of basic human rights.
M.Francis (Bedford, MA)
Another scientist weighing in and agreeing with Barbara on all points. To this I would add that if more people understood the "why" behind frequent hand washing with soap, the more likely they are to comply with CDC recommendations. The NYT has done a great public service with this very timely article!
Zetelmo (Minnesota)
@M.Francis We should have an article discussing whether Everclear or 151 rum would work as hand sanitizer.. Looks like it would, considering the high percentage of alcohol.