Lori Walsh: Hand sanitizer is a rare commodity these days, which means people are trying to make their own, including students at the University of South Dakota. Ranjiit Koodali is a Professor of Chemistry at USC and a frequent guest on In the Moment in Innovation, and he's joining us today.
Dr K., welcome. Thanks for being here.
Dr. Ranjiit Koodali: Oh, good morning, Lori. Thank you for having me.
Lori Walsh: Let's talk hand sanitizer because in some ways I was never a big hand sanitizer person anyway. I wasn't really sure about whether it worked or not. I was a soap and water person, so let's start with soap and water. What's the difference between just washing your hands with soap and water and using a chemical hand sanitizer? Is hand sanitizer better necessarily?
Dr. Ranjiit Koodali: Well, the hand soap is the preferred method of removing pathogenic microorganisms. And so if anyone that has access, ready access, to a bathroom and readily available soap and water, this is the recommended action by the World Health Organization, WHO, and the Centers for Disease Control and Prevention, the CDC, because soap has this unique ability to not only clean and remove dirt, but it can also kill a microorganisms like a viruses and bacteria. So using the hands soap is the best and most effective way to remove contact of bacteria and viruses physically from the hand, but there are instances where we may not have already access to soap and water, especially a sink in every room of an office or a university setting. So the hand sanitizer can be almost equally effective.
Lori Walsh: All right. What is it made of? What's a good hand sanitizer made of? Why does it work so well?
Dr. Ranjiit Koodali: Oh, absolutely. So the soap has got two components, watered allowing, it's called the hydrophilic, hydro is water, and philic is something that allows water. And so a hydrophilic component which has molecules that like water, H2O, and it also has got an organic component that hates water. So it's hydrophobic. So that's the ability of the soaps to remove both water and oil based dirts, but this hydrophilic component is one that is actually very effective to remove viruses and bacteria, and that's why hand sanitizers are all equally effective.
So the hand sanitizers that the CDC recommends is either ethyl alcohol or ethanol, the alcohol that we get from corn, or rubbing alcohol that is typically found in many households or also chemically known as isopropyl alcohol and propanol. So effectively alcohols are very good in revealing micro organisms like bacteria and viruses, especially for the kind of virus we are talking about, the COVID-19, the coronavirus disease 2019, and that's because these viruses normally, they have an envelope, an outer membrane, black structure, that surrounds the genetic material. And that envelope is made of fats, essentially, it's made of what we call a lipid bi-layer.
And those molecules on the outside, they have an affinity to be attracted towards molecules like water and alcohol. And that's why a solution of rubbing alcohol, or alcohol, is very effective in attaching itself to this envelope of the COVID-19 virus, and then disrupting the envelope. And in this manner, what happens is that the genetic material RNA, which is inside the envelope is now let loose, and then it has no means or methods to replicate the entire structure of the virus as it's destroyed. And this process is called lysis.
Lori Walsh: It's been so fascinating to me to hear how contagious this is. But then also how relatively easy it is to destroy just by washing your hands or by using a hand sanitizing wipe on your countertop, and then once it gets into your lungs, it can be devastatingly destructive. Why can one little virus be so easy to handle in some situations and so impossible in others?
Dr. Ranjiit Koodali: Absolutely. So this is something unique to the structure of viruses. They're not actually living organisms. They need a genetic material from a host to replicate. So these viruses [inaudible 00:05:28] generally they have this nucleic acid, DNA or RNA, not both. So the COVID-19 has the RNA. The RNA, it is surrounded by some protein molecules. And then you have this envelope of this plants, or what is called a bi-layer of lipids. And so this entire proteins, this genetic material, and this fatty acids, they're all held together by a process called self assembly. It is a recognition process where there are interactions that are relatively weak, so they can be formed very easily, but at the same time they can be ruptured easily. And that is the beauty of it.
So when we have hand sanitizers, like alcohols or a soap, the outer envelope in COVID-19 for example is consisting of these lipids, and these bond very strongly to the alcohol molecules and the envelope is completely destroyed and the genetic material has no other avenues to replicate. So this process of self assembly is very intriguing and interesting in the sense that on one hand it is easy to form these structures, but at the same time it is also easily effective to break down by using very simple chemicals that can be found in homes.
Lori Walsh: Let's talk about making your own hand sanitizer. What is happening first of all with the students at USD, and how they responded to the hand sanitizer shortage?
Dr. Ranjiit Koodali: So one of the things that administration has done is to provide guidance regarding social distancing. So a lot of our researchers are doing hands on experiments in the lab bench, so they're working with maintaining a social distance and avoiding contact with colleagues in their group. So the recommended guideline is one person to 120 square feet of space. So we are maintaining the guidelines by the CDC, FDA and trying to minimize contact with individuals, fellow students and faculty. So in terms of the hand sanitizers, actually the chemistry department has helped the Coyote community provide a homemade sanitizer, if you will.
And we prepared a hand sanitizer with an alcohol, the recommended guideline from CDC at least 60% by volume for the alcohol to be effective. So we had prepared a recipe that consists of an alcohol, that is the rubbing alcohol, we use isopropyl alcohol rather than ethyl alcohol. And we also added another component, glycerine. And the reason is that alcohols, especially ethyl alcohol or isopropyl alcohol, are highly dehydrating they can actually vaporize very easily. So in order to minimize the vaporization, we added a about one to 2% of glycerin. It is a little bit more viscous, so the alcohol will not vaporize very quickly when you rub it on on a surface of a keyboard or a lab space or door knobs, et cetera, or on hands for example.
And so a homemade product that's safe to use, but we need to ensure that the place that we prepare is clean. The container that we used, is sterile. And most importantly, the alcohol content by volume should at least be 60%, and typically the range is between 60 to 95%. We also need to add sterile water. It could be water like distilled water that we can buy from the stores or boiled water, for example.
Lori Walsh: Is this why some people were using aloe vera gel, sunburn lotion, that they had in their cabinets and mixing it with alcohol to make hand sanitizer? Is that a thing? Is that effective?
Dr. Ranjiit Koodali: So the main challenge with that, Lori, is one needs to be cognizant of the alcohol volume. So using a small emollient like aloe vera is okay, but the CDC guidance is to avoid adding any inactive ingredients. Sometimes some of them may be harmful if a child accidentally ingest. So the best recipe for homemade hand sanitizers is using rubbing alcohol, which a number of households happen to have. And I just was cleaning up my home, and we found rubbing alcohol. And so either rubbing alcohol, or alcohol, but the most important thing is the effective volume of alcohol should be at least 60% for the hand sanitizer to effectively remove any pathogenic organisms from surfaces or on one's hand. And so aloe vera can be used, but one needs to be aware of that the volume of the alcohol used should not go below 60%.
Lori Walsh: So if you have one of those bottles at home, is there something else in your home that you could use or do you have to order something in order to make homemade hand sanitizer? We just really have about two minutes left, but yeah.
Dr. Ranjiit Koodali: So Lori, the rubbing alcohol that can be purchased from the stores, they're quite effective. One can disinfect surfaces, points like doorknobs, handles, etc, that are frequently contacted, can be wiped using rubbing alcohol. That would by in in itself be very effective. And if one knows the concentration of the rubbing alcohol wouldn't dilute it with sterile water, but it should be at least 60 to 70% is recommended, but at least 60% alcohol is required for a hand sanitizer to be effective.
Lori Walsh: Interesting. So you could just make a home spray with alcohol to clean your door knobs and your high frequency surfaces as long as it had the right volume of the alcohol to some distilled water, and in a sanitized container.
Dr. Ranjiit Koodali: Absolutely. So that's what we have actually done in the chemistry department. Students have to, in addition to their research labs, have to use some common instruments in the department. So we actually prepared hand sanitizers near the, in the instrument room. So we have a written standard operating procedure for individuals using these common instruments. They are expected to wear gloves, they are expected to sanitize the area by spraying these alcohol solutions onto surfaces so that the instrument is not contaminated by any bacteria or viruses. So it's relatively easy to make a homemade product. As is rightly pointed out, the importance is to maintain the alcohol volume at least 60%.
Lori Walsh: Dr K., thank you so much for being here with us today. Stay healthy, and we appreciate your time.
Dr. Ranjiit Koodali: Thank you. And as always, it's a pleasure to be on SVP. We thank you, Lori so much.