How Hand Sanitizer Works & How to Use It

Now that hand sanitizer has transformed into liquid gold, it’s important to know how it works, what it’s good for, and how to use it.

First, let me undercut myself by saying that washing hands with soap and water is always the best option. Hand san, as I affectionately call it, is only for situations when soap and water is not available[i], and even using it, you should not consider your hands to be as clean as if you washed with soap and water.

Soap cleans hands or other surfaces by removing debris, including dirt, grease, chemicals, and germs. Hand sanitizers, on the other hand, deactivate many, but not all, bacteria and viruses, and do not remove anything.

Take a look at the back label of your closest hand sanitizer. Under “Use,” you’ll likely see words like “reduces” or “decreases” bacteria instead of words like “kills” or “cleans.” This is key to understanding what hand san is, and is not, capable of.

The most important part of a hand sanitizer is its active ingredient. This is the workhorse. The heavy lifter. The point in using it. Without a good active ingredient, at the right concentration, the whole product is useless.

There are several active ingredient options allowed for use in hand sanitizers by the FDA. Most common in the U.S. are ethyl alcohol, isopropyl alcohol, and benzalkonium chloride. Though it’s an FDA-allowed active ingredient, I’m not a fan of benzalkonium chloride. It may be less effective[ii] and is linked to antibiotic resistance[iii]. My focus here is on the alcohol-based hand sanitizers.

Ethyl alcohol is also called ethanol and is what you’ll find in cocktails. But don’t drink ethanol-based hand san – it’s too strong. And don’t make hand san with your favorite tequila – it’s not strong enough. (Save it for Happy Hour.)  

Isopropyl alcohol, also called isopropanol or rubbing alcohol, is what you’ll find at the pharmacy, usually at a concentration of 70% or 99%. There are quite a few other alcohols, including methanol, which I address below, but isopropyl alcohol and ethyl alcohol are the two that best combine safety and efficacy for hand sanitizing. 

How Alcohol-Based Hand Sanitizer Works

Alcohol-based hand sanitizers, at the right concentration, reduce the amount of certain bacteria[iv] and viruses[v] on your skin.

Bacteria, as living cellular organisms, are surrounded by a cell membrane made of lipids and proteins. (The word “lipid” derives from the Greek word for fat.) Viruses are not alive, but can be divided into two groups: enveloped and non-enveloped. Enveloped viruses are those that are surrounded – or enveloped – by a fatty lipid/protein layer. Common enveloped viruses are the virus that causes the common cold, influenza, and the coronavirus.

The cell membrane of bacteria and this envelope on certain viruses have something in common: they both contain lipids and proteins. This is what alcohol uses against them.

Alcohol is an amphiphilic molecule, which means one end is hydrophilic (water-loving) and the other is lipophilic (fat-loving). The lipophilic end of the alcohol molecules attaches to the lipids in the outer layers of bacteria and enveloped viruses, dissolving them and ripping the surface of the germ apart. Alcohol additionally pounces on the proteins in the membrane or envelope plus any that spill out from inside. Alcohol breaks down the structure of proteins in a process called denaturing. It’s one-two punch[vi] that is very satisfying to think about.

Woohoo! I want that in my corner! Except…

There are some common germs that alcohol doesn’t work against such as norovirus (the scourge of schools and cruise ships), cryptosporidium (a microscopic parasite), or Clostridium (a bacterial spore)[vii]. And remember, hand sanitizer does not remove any dirt, oils, or chemicals. Further, when hands are too soiled with dirt or grime, the hand sanitizer probably cannot even reach the target germs[viii].

This is what makes soap and water the better option.

How to Use Hand Sanitizer Effectively

The CDC, FDA, and Mayo Clinic agree on the best way to use hand sanitizer to maximize efficacy:

  • Coat surfaces of your hands[ix] with the wet sanitizer. Include your palms, back of hands, and fingertips.
  • Rub your hands thoroughly until hand sanitizer is dry.
  • Do not wipe off wet hand sanitizer. It needs to stay on hands until it evaporates to do its job. Keep rubbing your hands until dry.

Three Common Mistakes When Using Hand Sanitizer

  • Using too little
  • Rubbing too short a time
  • Wiping it off before dry

I get it. Hand sanitizer has been hard to find, so you want to conserve it when you have it. However, trying to conserve it by using a small amount is pointless. Using too little hand sanitizer doesn’t work. You may feel like your hands are cleaner, but that is a false sense of security.

Why 60% and Not 100%

As the FDA says, “If soap and water are not available, CDC recommends consumers use an alcohol-based hand sanitizer that contains at least 60% alcohol.” It begs the question, though, if 60% alcohol is good, wouldn’t 100% be better?

Alcohol at too high a concentration poses a couple of problems. First, the alcohol evaporates too quickly off the skin, before it can reach its full germ-killing potential. The diluting water content keeps the alcohol on the hands longer, allowing it to work against the germs longer.

Secondly, alcohol is very drying, and the higher the concentration, the more drying it is. 100% alcohol, used regularly would be so drying as to damage the skin, causing it to crack and bleed and making it more vulnerable to infections. This defeats the ultimate purpose of keeping you healthy.

On the other end of the spectrum, hand sanitizers with alcohol concentrations below 60% are too diluted to address all the potential germs.

During the initial hand sanitizer shortage, there was a surge in DIY hand sanitizer recipes blazing up the Internet. These used various beverage alcohols such as vodka. However, most drinking alcohols contain an alcohol content less than 40% and therefore would not make effective hand sanitizers. Put them to use in your favorite cocktail instead.

The Problems with Making Your Own

While the FDA has given temporary authorization to pharmacies and alcohol manufacturers to produce alcohol-based hand sanitizers, the FDA does not recommend individuals make their own. Their concern is either that individuals will inadvertently make an overly-diluted, ineffective product that gives a false sense of security, or that home-made formulations could cause burns or other harm.

What’s with Methanol and the FDA List of Hand Sanitizers Not to Use?

Methanol, aka methyl alcohol or wood alcohol, is used in the creation of fuels, solvents, and pesticides. It is poisonous to humans but has been showing up in hand sanitizer products that claim to contain ethanol. Numerous people have been hospitalized and have died because of this. The hazards of methanol to humans are significant and well-known. Symptoms are wide ranging, from loss of vision to loss of consciousness and death, and may not be immediately apparent.

Methanol won’t be listed on a label. To avoid it, refer to the FDA’s list of toxic hand sanitizers, which currently stands at 115 products, and further avoid other products made by those manufacturers, just in case. The best bet is to buy from trusted brands. And never ingest hand sanitizer.

Also, on this list are a few hand sanitizers found to have insufficient alcohol concentrations, which leads to reduced effectiveness and a false sense of security.  

Why Does a Lot of New-to-Market Hand Sanitizer Smell So Bad?

It seems like everyone is getting into the hand sanitizer business these days. Anyone with the means to produce alcohol – from industrial plants to perfumeries to breweries – have made their way onto the bandwagon. It’s an impossibly easy market to jump into at the moment. Furthermore, demand for hand sanitizer is so high[x], that consumers may be taking what they can find, with less regard for quality, sourcing, packaging, ethics, price, or even smell.

One FDA requirement is that the alcohol in hand sanitizer be denatured. This is a different definition of “denature” from what I mentioned above regarding proteins. This means something must be added to the alcohol that makes it so unpalatable no one will be tempted to drink it. It’s a safety consideration because consuming 60%+ alcohol would quickly lead to alcohol poisoning.

Usually this means manufacturers use denaturing agents that make the product smell good but taste bad, such as with certain essential oils or bittering agents. However, now, some manufacturers are throwing all manner of cheap junk into the hand sanitizer to meet this denaturing requirement. These agents not only taste bad but smell worse. They certainly make not touching your face all the easier.

How to Buy Good Hand Sanitizer

  • Read ingredients. For so many reasons, read ingredients. Look for an active ingredient of ethyl alcohol over 60% or isopropyl alcohol over 70%.
  • Avoid “alcohol-free.” The term may sound like a benefit, but it could indicate that the active ingredient is benzalkonium chloride, which as stated above, is less effective than alcohol.
  • Check the FDA List of toxic hand sanitizers. Avoid mentioned products and their manufacturers.
  • Don’t believe outrageous claims. If it sounds too good to be true, it probably is.
  • Ignore “FDA-approved.” This is a marketing gimmick. Outside of pandemic times, all hand sanitizers must be registered with the FDA and are considered over-the-counter (OTC) drugs. However, the FDA does not authorize the use of the statement “FDA approved.” This term is used by a manufacturer in order to make their product seem more authorized than another.

Best Hand Hygiene

The best way to keep your hands clean is by a good washing with soap and water. Should I say it again?

I learned a ton in researching this article. Whew! Makes up for not taking Microbiology or Organic Chemistry in college! Maybe not quite. To give your brain a workout, read through the research I’ve cited. Even as a lay person, I learned a lot about chemistry, biology, and the world around me, and how best to interact with it.


[i] FDA. “FDA issues final rule on safety and effectiveness of consumer hand sanitizers,” https://www.fda.gov/news-events/press-announcements/fda-issues-final-rule-safety-and-effectiveness-consumer-hand-sanitizers.

[ii] Alberto Berardi, et al. 2020. “Hand sanitisers amid CoViD-19: A critical review of alcohol-based products on the market and formulation approaches to respond to increasing demand.” International Journal of Pharmaceutics, Volume 584, 119431, ISSN 0378-5173, https://doi.org/10.1016/j.ijpharm.2020.119431.

[iii] Kampf, Günter, 2018. “Biocidal Agents Used for Disinfection Can Enhance Antibiotic Resistance in Gram-Negative Species.” Antibiotics 7, no. 4: 110, https://www.mdpi.com/2079-6382/7/4/110/htm.

[iv] Kampf G, Hollingsworth A. “Comprehensive bactericidal activity of an ethanol-based hand gel in 15 seconds.” Ann Clin Microbiol Antimicrob. 2008;7:2. Published 2008 Jan 22, https://ann-clinmicrob.biomedcentral.com/articles/10.1186/1476-0711-7-2.

[v] G. Kampf, “Efficacy of ethanol against viruses in hand disinfection, Journal of Hospital Infection,” Volume 98, Issue 4, 2018, Pages 331-338, ISSN 0195-6701, https://doi.org/10.1016/j.jhin.2017.08.025.

[vi] McDonnell G, Russell AD. Antiseptics and disinfectants: activity, action, and resistance [published correction appears in Clin Microbiol Rev 2001 Jan;14(1):227]. Clin Microbiol Rev. 1999;12(1):147-179, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC88911/.

[vii] Gold NA, Mirza TM, Avva U. Alcohol Sanitizer. [Updated 2020 Jun 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan, https://www.ncbi.nlm.nih.gov/books/NBK513254/.

[viii] Todd EC, et al. “Outbreaks where food workers have been implicated in the spread of foodborne disease.” Part 10. Alcohol-based antiseptics for hand disinfection and a comparison of their effectiveness with soaps. Journal of Food Protection. 2010;73(11):2128-2140, https://doi.org/10.4315/0362-028X-73.11.2128.

[ix] CDC. “Show Me the Science – When & How to Use Hand Sanitizer in Community Settings,” https://www.cdc.gov/handwashing/show-me-the-science-hand-sanitizer.html.

[x] Alberto Berardi, et al. “Hand sanitisers amid CoViD-19: A critical review of alcohol-based products on the market and formulation approaches to respond to increasing demand,” International Journal of Pharmaceutics, Volume 584, 2020, 119431, ISSN 0378-5173, https://doi.org/10.1016/j.ijpharm.2020.119431.

50 thoughts on “How Hand Sanitizer Works & How to Use It

  1. I just came across an article that posts a tool where you can type in a cleaning product’s EPA number and it’ll tell you whether it’s approved by the EPA to be effective against COVID 19. The label on Dr. Bronner products can be difficult to read but I don’t believe I was able to find one on the Castile Soap labels. Are these products not effective when it comes to disinfecting against the virus……?

    • Hi Esmeralda- There’s a lot of information out there to sort through, isn’t there? The term “disinfectant” is regulated to apply only to EPA-registered products that chemically destroy disease-causing pathogens or other harmful microorganisms when applied to hard surfaces. Our Castile Soap and Sal Suds, our household cleaner, are effective cleaners, but not EPA-registered chemical surface disinfectants, because they do not kill germs. Instead, detergents and soaps, including our products, work effectively by latching to dirt, germs, and grime and rinsing them away, leaving clean surfaces and hands behind. Dr. Bronner’s hand sanitizer is an Over-The-Counter drug categorized as an antiseptic hand rub listed with the FDA, also not as an EPA-registered surface disinfectant. Hand sanitizers, also known as antiseptics, may be used on hands to lower the number of germs when soap and water are not available.

  2. What about aloe vera hand sanitizer (assured). Elthyl Alcohol 70%
    Distributed greenbriar international INC.
    MADE IN MEXICO
    I had this 6 months

  3. Hi Lisa, I love this article and have been using your lavender hand sanitizer. Can you confirm that the Dr. Bronner’s lavender hand sanitizer has 60% ethyl alcohol? The print is too small for me to read and on Sprouts website, the ingredients listed do not include alcohol, they just list lavender …
    Thanks, Kris

    • Hi Kris- It’s great that you’re reading labels. Here’s the full list of ingredients in our Lavender Organic Hand San: 62% Organic Fair Trade Ethyl Alcohol, Water, Organic Glycerin, and Organic Lavender Oil.

  4. This is a great article on hand sanitizer. Yours is my favorite, unfortunately, I have been trying to get more for MONTHS and can’t seem able to. Why can’t you produce enough to keep up with demand?

    • Hi Patti- I absolutely hear you. I know it has been frustrating. Our hand sanitizer sales are up over 250% from this time last year. While we have the raw materials for the sanitizer itself, our constriction point has been the machine capacity. We have even suspended our production of our hair care products, which are made and bottled on the same machines, in order to devote the machine time to hand sanitizer. We have been adding more machines – which must be both certified for organic standards and approved for FDA OTC (over-the-counter drug) standards. The supply has been steadily ramping up and should be much smoother coming into the fall. Thank you for bearing with us.

    • Hi JD- In fact, Castile soap is primarily designed for the body. The blend of oils (coconut, olive, palm, jojoba, and hemp) are designed to be the most nourishing to our skin. It is because it is such a simple soap that it cleans so many other things amazingly well. For body, use a small squirt in hands or on a wet cloth. For hands, 3-4 drops will do, or use a foaming soap dispenser with 1 part soap and 3 parts water.

  5. Thank you for presenting this informative article. I appreciate all of the effort you put into your research for this easy read. Love your products and your company and family’s efforts toward making the world a better place.

  6. Great article! Everyone who uses sanitizers should read this. Thank you!

  7. Thank you I would love to order some from you please send me the link

    • Hi David- Here’s the link to our webstore: https://shop.drbronner.com/. As you can imagine, we’ve been experiencing increased demand. If you don’t see hand san listed, or can’t add it to your cart, check back later. More inventory is being added regularly.

  8. Lisa,

    I’m a chemist, and would like to commend for one of the – no, the most well researched article I’ve seen on the subject. I particularly appreciate that you delve into the details and why they are important. By this I mean why washing is important, why 100% alcohol is not necessarily better than 60%, and the importance of not wiping it off. People tend to remember better when the understand, rather than just memorize, use rules.

    I’m a big fan of Dr. Bronner’s products – even that tube of peppermint toothpaste that was so thick I thought I’d need a vice to squeeze it out :). Don’t worry I adjusted the viscosity was spring water and it was fine within a few days 🙂

    • Hi Jim- Thanks for reading, and for your kind words!

  9. I love your lavender hand sanitizer, been using it from the beginning. Found it at Sprouts and Trader Joes has it once in awhile as well. Thank you for the article, very informative. Stay Well everyone <3

    • Thank, KT. I do always enjoy a good research project!

  10. Thank you. I learned good news about handwashing versus hand sanitizing.

  11. I have a number of bottles of hand san. Some are samples that I have had for some time and some that I was able to purchase just as the pandemic started and a couple since they came back on the market.

    One issue that I have regarding the FDA list is that if I am at the store and see hand san, even if I read the label, how, without the list, do I know if I should buy that hand san??

    Also, if I do get a hand san that smells really bad, can I add essential oils to it to make is smell better? would that be an issue?

    • Hi Leanne- I agree that consulting the list is a pain. Hopefully you can identify some brands you can trust and look for those. I know this is not a convenient suggestion, but other than pulling the list up on a smart phone, you could also print it out. I know that’s a hassle. You can add a couple drops of essential oil to the hand sanitizer. You would not want to do more than a couple drops as essential oils can burn the skin at too high a concentration, and they can dilute the alcohol.

  12. Please can you make a larger size of your hand sanitizer! It would be more environmentally friendly if we could refill the small bottles…

    • Hi Charlotte- Thanks for your suggestion! I’ll share it with the team.

    • Hi Arlene- I’m sorry you’ve had trouble purchasing our hand sanitizer. It’s been in high demand as of late! Know that we’ve increased production of it. Our webstore team adds more product and updates the page often, so continue to check back regularly. Many natural grocers and health food stores also carry our hand sanitizer and other products.

    • Hi Ellen- All of our products can be purchased from our webstore at https://shop.drbronner.com/. As you can imagine, hand sanitizer is in high demand these days, but we have ramped up production. If we are out of stock, please keep checking back as inventory is added regularly.

  13. Love and Gratitude, Lisa Bronner. Excellent article, in fact the best I’ve read on the subject of hand sanitizers.

  14. Really lovely, well written article. Clear, concise and informative. Thank you Lisa, and the whole Bronner family!
    I would LOVE for your hand sanitizer to come in gallons or large something. So I could refill the millions of little pump bottles I have!
    All my Love is One!
    ~Your adoring customer for Life

    • Thank you, Sita! I’ll share your request for a refill size.

  15. Thank you for the info…….I mostly luse hand sanitizer when I am doing little things around the apt…..and I always wash my hands w/soap and water…….I would say at least 20-25xs a day…….
    I am on Dr.Bronner e-mail.
    Is yours different than the company?
    Tony C

    • Hi Tony- Good on you for diligent handwashing! My articles are nearly always included in the Dr. Bronner’s eNewsletter, and I also send an email alert when a new article is published. There is an option to subscribe at the bottom of my homepage, https://www.lisabronner.com/.

  16. Outstanding article. I always walk away with very useful information. I also love your hand sanitizer and always keep it in the cars. Excellent post and thank you for sharing your research.

    Margarita

  17. Thank you for this great information! I actually read on one of my hand sanitizers NOT to wipe my hands together after spraying, so this is an important deviation from that. I love your peppermint hand sanitizer and managed to purchase a a case before the world went crazy.

    • Thanks, Trisha! I’m glad you found the article helpful.

  18. Why is it so very hard to find hand sanitizer that has isopropyl alcohol? I’ve read that ethyl is not good.

    • Hi Allyson- This was not something I found reflected in the studies I read. In fact, there was more evidence that ethyl alcohol was slightly more effective against enveloped viruses than isopropyl. Also, ethyl alcohol is effective at a lower concentration (60%) than isopropyl (70%). This is reflected in the temporary authorizations for hand sanitizer that you’ll see linked in the article. Perhaps the lower needed concentration is why you are seeing more ethyl alcohol? However, it could just be that there is such a scarcity of hand sanitizer in general right now. Neither alcohol has harmful side effects to the skin beyond causing dryness.

  19. Oh my gosh, you did a wonderful job on this post! I am a nurse and I love how you presented this information! Yes, hand washing is best and I wash with Dr. Bronner’s in my home 🧼 💕

    • Hi Leah- I take that as high praise coming from a nurse. Thank you, and stay safe & healthy!

  20. What about Witch Hazel? ? ? I have been using either my Bronner spray hand sanitizer (I have 3 of them) or my homemade hand sanitizer for years. I use witch hazel and Lavender essential oil by Doterra (sp). or Lemon EO.

    • Hi Deborah- I’ve found a few interesting studies on the antimicrobial properties of witch hazel, but nothing to confirm that witch hazel on its own kills germs near the effectiveness of the alcohols. I would not rely on it as an alternative to soap and water. Using witch hazel on hands isn’t harmful in any way. But unfortunately, it is not as effective as alcohol when you’re away from hand washing facilities. We see witch hazel in facial toners because it is an astringent and also protects the elasticity of the skin.

  21. Thank you for all the great information. The FDA just scares me, what good are they? There are so many things out there that say FDA approved, but with all the information we have now, it seems the FDA has allowed to many bad things into our products so we’re in this position now. Thanks for all you do to make us aware of these issues.

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