What's in Hand Sanitizer? | Ingredients With George Zaidan (Episode 9)

What's in here, what's it do, and can I make it from scratch ingredients?

Now, you might already know that the ingredient in here that kills germs is ethyl alcohol—or, as we purist chemists like to call it, ethanol—which is exactly the same molecule that gets you drunk. But you cannot sanitize your hands with vodka or almost any other liquor, beer, or wine because the ethanol concentrations are just too low in the stuff you drink. A hand sanitizer needs to be in the 60 to 95% range to effectively kill the germs that make you sick.

So, you just dilute your pure ethanol down to, oh, I don't know, 70%, and there you go: hand sanitizer. Except we consumers are needy. Not only do we want our products to work, we also want them to be convenient. Imagine trying to apply a completely liquid, free-flowing hand sanitizer when you are out and about. This is not safe! It's in my pants!

We also hate dry skin, and unfortunately, alcohol is really good at drying out your skin. As if that were not enough, we’d also like our products to smell nice, like these flowers. And these are all actual hand sanitizers that people buy: marshmallow pumpkin latte, fresh sparkling snow, white peach chardonnay, and I less than three glitter. Even though we want our sanitizer to smell delightful, we also want it to taste terrible so that people who cannot get alcohol legally or who want literally the cheapest alcohol possible don't drink sanitizer instead.

So, that's why hand sanitizers are not just ethanol and water. So let's look at what else is in here. Okay, so we got our ethyl alcohol 70%. We knew that. Aminomethyl propenol and fragrance, or as the French say, "ba." Now, naturally, my first step was to call the manufacturer and ask them what each ingredient does, but they do not disclose that information. So, we're going to have to make some educated guesses like a chemical detective.

Luckily, we have clues. Now, on the manufacturer's website, they say that they add four skin conditioners to prevent the drying effects of alcohol. They also say that they add bitter, unpleasant-tasting chemicals to prevent people from drinking this. As you know, like alcohol. All right, so the conditioners—that's actually the easy part because caprylyl glycol, glycerin, isopropyl myristate, and tocopherol acetate—which, by the way, is chemically very similar to vitamin E—are all pretty widely used in cosmetics as lubricants or thickeners or humectants, which help retain water.

The gel is also easy. Usually, if you see the word polymer in the ingredients list of a gel, that polymer is what makes the gel a gel. Okay, so we're left with isopropyl alcohol, aminomethyl propenol, and fragrance. Now, aminomethyl propenol is used as a pH adjuster, but it's also said to have a faintly amine-like odor. Now, amines generally smell like fish or decay, so that could be our "please don't drink me" chemical. Isopropyl alcohol, on the other hand, does not smell bad, but it is said to have a faintly bitter taste, so that could be it. And then there's fragrance, and that could smell good or taste bad. We'll never know lost.

But now that we've mostly figured out what's in hand sanitizer and how it works, I'm going to try and make my own from scratch using only natural ingredients. I'm going to start with ethanol—uh, this is 99%—and to make it smell delightful, I'm going to add rosemary essential oil. Now, here is where things get a little bit complicated. In the hand sanitizer you buy at the store, I think the jelling agent is acrylates C10-30 alkyl acrylate crosspolymer, which, to my knowledge, has no natural equivalent, or at least no easily findable natural equivalent.

Now, the two most common natural gelling agents are gelatin and agar. And my first thought was, I'm going to use gelatin and make hand sanitizer jelly. But then I thought, maybe adding 99% ethanol to gelatin, which is a protein, will just basically cook the protein in the gelatin with the alcohol. So, I thought, I'll try agar instead. And I have no idea if it'll work, but there's only one way to find out.

We'll let it set and see what happens. Oh no! The agar just came out of solution, and the ethanol-water mixture is just floating on top, and it's not even remotely gel-like. It looks just as liquid as when I poured it in. So, that was a failure. I think 70% alcohol is just too much alcohol for the agar to gel. Yes, this would probably sanitize my hands just fine, but it's so liquidy I might as well just mix alcohol and water, and then I wouldn't have the weird egg white mess at the bottom.

So, I give this recipe a zero. A big old zero out of ten! And if you guys have suggestions on how to fix it or help me even get to a 1 out of 10, they would be greatly appreciated. Let me know in the comments or tweet at me! Um, yeah.