What’s in Air Freshener? | Ingredients With George Zaidan (Episode 6)

What's in here? What does it do? And can I make it from scratch? Spoiler alert: I actually can't, but the reason is fascinating.

Ingredients. Now, there are a lot of different ways to get scents into the air. But if you're actually interested in what those scents are chemically, you're not gonna have a lot of luck looking at the ingredients of a product like this. Now, you could go to the manufacturer's website, where you will find a list of every single perfume scent and fragrance they use in every single one of their commercial products. But as this list is 20 pages and over 2,000 items long, I don't see it being much help.

And this is where your nose comes in. Well, your nose and also the front of the label. Because if a product is designed to smell anything like oranges or lemons, it probably has a chemical called limonene, or also limonene in it. Limonene is a terpene, which is a type of chemical that tends to smell pretty strongly.

Now, by itself, limonene is not really that toxic. But when it reacts with ozone, something happens that an old chemistry professor of mine used to affectionately call a HBL, or "all hell breaks loose." In other words, a lot of different stuff is formed, and one of the main products is formaldehyde.

Now, formaldehyde is not really good for you to breathe in; it's an irritant. And if you're chronically exposed to it, it’s probably a carcinogen. Okay, before we freak out, remember that all toxicity is dose-dependent. Meaning that if you huff concentrated formaldehyde, yeah, bad things are gonna happen to you. But if one molecule wanders into your nose, you're gonna be just fine. Also, formaldehyde is only formed when limonene reacts with ozone.

Now, ozone is that oxygen mutant that's in a thin layer of our atmosphere, protecting us from a lot of the sun's UV rays. But it turns out there's enough ozone down here at ground level and in your house to react with limonene and produce formaldehyde. But look, if you're just printing a couple of times a week, relax; it's not anywhere near enough to hurt you.

But there are theoretically ways to produce unsafe levels of formaldehyde in your house, pal. Well, shockingly, you can actually buy a product that makes a lot of ozone on purpose. These things are marketed as air purifiers. Even though they don't check the description, I will post the link with more information. You can also buy products that are designed to constantly emit limonene, say a gel or a plug-in.

And let's say you've got both of these going right next to your ozone generator, 24 hours a day, right next to the bed where you sleep, without ever opening up the windows. You could be generating enough formaldehyde to cause issues. Now, that's a very unlikely worst-case scenario. But if any of you out there are sitting right next to your ozone generator and have four air fresheners surrounding you, just, you know, give me a call; we need to talk.

But back to limonene. The crazy thing is limonene is not made in some far-off toxic chemical plant; it's made in a literal plant. Yep, limonene is the main component of orange essential oil, and it's present in a bunch of other citrus fruits too. So that all-natural air freshener recipe you found on Instructables or, God help us all, Pinterest—the one that tells you to add a boatload of orange essential oil—has literally the same chemical in it as the gel or plug-in you buy at the drugstore. Go figure.

I actually like Pinterest, so just to make things difficult, let's say I wanted to make an air freshener without using limonene or any other essential oil. You might have read right here on the interwebs that the best, easiest, and most natural air purifiers are plants because there's evidence that microbes living in the plant root systems, and actually the plants themselves, can literally eat formaldehyde and other indoor air pollutants.

So there, I made an indoor air freshener. Except I didn't. We don't actually know how well potted plants like these purify or don't indoor air. Researchers at Drexel University are trying to figure this out by building a giant wall of plants indoors and then circulating the building air around the root systems to see if that makes any difference. Until I figure that out, we've got a couple of options for homemade air fresheners.

Now, if you usually use an air freshener to cover up a bad smell, then the best from-scratch, all-natural solution is to get rid of whatever is making the bad smell and open a window. But if you want to add a nice citrusy scent to your room, then you could just take some orange peel, throw it in some boiling water, and that will release our old friend limonene, just like a commercial air freshener would.

So if you guys have any thoughts on limonene, air fresheners, ozone, or, you know, Pinterest recipes, let me know in the comments. And if you have an idea for an episode, hit me up on Twitter. In the meantime, stay fresh!