If you've ever spent time looking at your hand sanitizer bottle – and you might, now more than ever – you've probably seen the myriad little air bubbles suspended throughout the sanitizer. You might have wondered if they're meant to be there. You may wonder what purpose they serve (if any). So what's the story?
Well, for one thing, the bubbles are not "meant" to be there, but they're nearly impossible to remove. That's why virtually every image you see has bubbles in it, even the official product photos published by the people making and selling the hand sanitizer.
Some formulas of hand sanitizer have more bubbles than others. Some don't have any in their product photos, but then, we all know how product photos can be staged or faked. A bottle of hand sanitizer with no bubbles in it might actually just be a bottle of glycerin or water, staged for the photo. It doesn't really matter, after all, since the proof is in the pudding; your hand sanitizer bottle has bubbles in it.
You can technically remove the bubbles if you'd like. It takes either some advanced equipment or a lot of time and patience. This person meticulously sucked them out using a syringe. Other people have used vacuum tubes to achieve a similar effect by removing the air from the bottle. You can remove some bubbles simply by shaking, squeezing, and spinning your bottle.
What Are The Bubbles in Hand Sanitizer?
The first and easiest question to ask is this: what even are those little bubbles? Some people theorize that they're a byproduct of alcohol-eating bacteria. Since alcohol is the primary ingredient in hand sanitizer, the bacteria could just infest the sanitizer, eat the alcohol, excrete air, and thrive.
There are bacteria that eat alcohol, that much is true. They're pretty much everywhere because they're in the air itself. It would be impossible to produce hand sanitizer without exposing it to them at some point.
The same goes for every other kind of alcohol, though. Does your bottle of isopropyl in your medicine cabinet get consumed by these bacteria? Does the scotch on your shelf or the beer in your fridge?
Technically, yes! These bacteria convert alcohol into vinegar, which is why wine goes bad over time if it's not stored properly.
Of course, any company producing hand sanitizer would add ingredients to prevent these bacteria from reproducing, if indeed they are a problem at all. Since bubbles in hand sanitizer are ubiquitous, though, you can pretty safely assume that that's not the cause.
Indeed, the real cause of the bubbles is much simpler. It's… just air.
How Do The Bubbles Get There?
If you take a bottle of any liquid and shake it, the air gets mixed into the liquid. For something like water, that air quickly works its way to the top of the container, burst, and settle. The air separates out of the water.
For something like a carbonated beverage, the liquid is saturated with carbon dioxide. Some of the CO2 naturally escapes, which is why your soft drinks fizz and bubble. When the liquid is more agitated, like when it's poured, it froths up, which is where the "head" on beer comes from. If you take a bottle and shake it, which stirs up the CO2 and separates it, it froths out rapidly. The coke and mentos experiment is a prime example of those bubbles escaping all at once.
With hand sanitizer, the air bubbles stay in place because the liquid is so thick. The bubbles can move, very slowly, but generally, the thickness of the liquid holds them in place.
So how did they get there in the first place? As it turns out, they're actually added intentionally. Purell was the pioneer of this method, all the way back in the late 1990s. A company named Gojo was founded in 1946 to create hand cleaners, and in 1988 created Purell. Even back then, it was just another cleaner, rather than the extremely popular item it is today.
The revolution came in the late 90s when the company Nottingham Spirk entered the picture. Nottingham Spirk is a company specializing in marketing, innovation, invention, and disruption. They take existing product ideas – with permission and a consulting fee from the owners, of course – and enhance them. They're responsible for things like the Swiffer Sweepervac, the Crest Spinbrush, the Dirt Devil vacuum cleaner, and more than 1,000 other products.
One such enhancement, to Purell, was the clear bottle packaging and the addition of bubbles. Why? To give it a fresh, clean look and an appealing aesthetic. Clear liquid with fresh, clean bubbles, in a clear, clean packaging, is all a psychological trick to make you think the whole thing is fresh and clean. If the cleaner is clean, it must be able to clean your surfaces cleaner!
Of course, even then, Purell wasn't the number one hand cleanser for another few years. That break came about in 2002 when the CDC tested and discovered that alcohol-based hand sanitizers were the next best thing beyond hand washing when it comes to cleanliness.
Gojo's isn't the only company that produces hand sanitizer these days. Some sanitizers include bubbles, and some don't. So what's going on?
Well, we haven't done the research, but given the Nottingham Spirk modus operandi, chances are they are the ones who own the patent to the process that adds bubbles to hand sanitizer. They can then license out that patent to companies like Gojo to make Purell, or to store brands to make their own versions, or for off-brands like Air Co or Germ-X to make their own. Then again, looking up non-Purell hand sanitizer shows a lot of low-bubble sanitizers, so perhaps only Gojo can use that process. Whether that's because no one else wants to pay for it, or because it's exclusive, we don't know.
Some bubbles will naturally make their way into any hand sanitizer, or any other viscous liquid. Simple shipping and handling will jostle around the gel, and air can get into the product through this handling. It's typically not going to be as much as you get from the actual commercial process Purell uses, but it's enough to be visible, particularly with hand sanitizer you've used for a while. Or perhaps not! Sometimes that handling is what shakes the bubbles out of the bottle.
Why Do Some Sanitizers Bubble and Others Don't?
Hand sanitizers can be made from a variety of different formulas. Some of these formulas are little more than alcohol, water, and a gelling agent to turn it into the thick gel we use rather than a thin liquid. Others have additional ingredients in them that add to their qualities, like soap to help break up greases, or foaming agents to make them bubble more when used.
Hey, we might be onto something here.
Foaming agents in hand sanitizer generally work through either agitation or through exposure to air. In a bottle, hand sanitizer isn't going to really foam up, but when it's squirted out and rubbed around, a lot more air gets to it and it foams more.
Some foaming hand sanitizers also have special nozzles on their bottles, which mechanically foam up the stuff as it dispenses. This helps you get full coverage with hand sanitizer without using too much of it. Soap dispensers can work the same way, as you see in many public restrooms.
You can also consider the usage of the hand sanitizer. Sometimes, two bottles of the same sanitizer can have different levels of bubbles. Typically, this means one is handled more than the other. The one handled more often, jostled around, can shake the bubbles loose and let them surface and break. Though, depending on how violently and how often the bottle is shaken, it can even add more bubbles. Especially if it's frequently turned upside down!
The fact is, while Purell adds the bubbles as part of their branding and the aesthetic of their product, other companies don't have to if they don't want to. You've probably heard some of the news stories about breweries converting their machinery to produce hand sanitizer, right? To make up for the national shortage, these facilities are converting to work from one alcohol product to another. They also often have pictures or videos showing bottles of freshly-produced hand sanitizer. If you look carefully, you can see that there's no bubbles in sight.
These bottles haven't been jostled around, shaken, or shipped, and there's no reason for the company to add bubbles for the aesthetics when their product is meant to be purely functional.
Are Hand Sanitizer Bubbles Bad?
You might wonder if the bubbles in hand sanitizer are bad in some way. After all, if you Google search the question, you'll come across people wondering if it's a sign of alcohol-eating bacteria, or if it's a sign that the chemicals are breaking down, or anything else. There are a ton of different theories put forth as fact by people who don't know one way or the other - maybe they heard a rumor from someone who heard it from a friend who heard it from an official at a company that tests these things. Who knows how these rumors start.
The fact is, there's zero threat behind those little bubbles.
They're just harmless air bubbles, and they aren't going to hurt you in any capacity. When you use hand sanitizer, the bubbles pop and go away, and they don't get in the way of fully covering your hands with the sanitizer as part of a hand cleaning ritual. 
The bubbles are small, so the space they take up is equally small. Maybe a bottle with bubbles gets you a drop or two less hand sanitizer than a bottle without bubbles, but we're talking a fraction of one use of hand sanitizer here. It's nothing to get concerned about; it might cost you a penny over your lifetime of using hand sanitizer, all told.
The bubbles are not in sufficient quantities to pose any manner of health risk. With most hand sanitizers, these little bubblers are simply air or CO2 that has been injected into it, like they do with soda carbonation. You would have to try very hard to accumulate enough air from hand sanitizer bubbles to even get a lungful, and at that point, you have much bigger problems.
As mentioned, the bubbles either come about because of the hand sanitizer being shaken up and aerated, or from a company intentionally injecting bubbles into the gel itself as part of the production process. This means there's no chance that it's part of a decomposition process, as the "alcohol-eating bacteria" might imply. There may be bacteria living in the hand sanitizer, just like there are bacteria living on the moon, at the bottom of the ocean, and in the air, but it's no more dangerous than any other bacteria you encounter.
To make a long story short, in any case, the bubbles in hand sanitizer are harmless. They may have an interesting origin as a marketing tool and a psychological pressure, but they aren't going to hamper the efficacy of hand sanitizer in any way. Don't worry about them, and feel free to tell the story of Purell's bubbles to your curious friends. It's really kind of neat!
