One question that comes up again and again in my community is how to improve indoor air quality. And one answer is repeated often: just use plants. Sounds good, right? Plants are cost-effective, pretty, and all-natural. What’s not to love?! Well, if you’re actually wanting to remove toxins from your home, running out and buying plants shouldn’t be your first step.
This might surprise you because plants are often touted as the solution to indoor air pollution. I think that’s because a lot of articles like to jump on “quick and dirty” answers to complex questions. Well, as much as I love quick and easy solutions, they also have to actually do what you want them to do. So, as always, my focus is to help you reach your healthy home goals the best way possible. And sometimes, that means debunking some popular myths.
Now, I think it’s only fair that I let you know right off the bat that I am not a plant expert. My idea of the perfect plant is one that takes very little effort because I kill houseplants faster than I care to admit. So when I started getting asked about air purifying plants, my go-to resource became a study done by NASA.
The space agency worked with the Associated Landscape Contractors of America to test specific plants’ abilities to remove common indoor air pollutants. The study has been widely referenced but often misrepresented.
While it demonstrates the ability of plants to remove certain contaminants from the air, it has a limited application to the real-life application of reducing toxins from our homes. Here’s why:
1. They tested the plants in sealed containers, exposing them to one chemical at a time. This is similar to regulators and product manufacturers testing our body’s response to one ingredient at a time. Our homes are filled with much more than just one chemical but the study doesn’t look at how plants cope with this type of environment.
2. The container volume was less than 1m2 (~10ft2), whereas a typical room in a home would be many times larger. Our homes also “breathe”, with the volume of air being replaced many times a day.
3. The soil quality and area exposed to air impacted removal efficiencies. I’m not in the habit of using fertilizer for my indoor plants. And while I already admitted to not having a green thumb, I’m willing to bet I’m not alone in this.
4. Most homes aren’t equipped with activated carbon fan filters. This is recommended in the study as “an integral part of any plan using houseplants for solving indoor air pollution problems.”
So, the plants tested may be able to remove indoor air pollutants from the air, but it’s unknown how well they perform in an actual real-life house. It turns out I’m not alone in my thoughts on this. But needless to say, adding more plants to your home can have other benefits beyond removing things like formaldehyde and benzene. So if you’re looking to increase your greenery, it doesn’t hurt to use some plants that may be better than others at cleaning the air!
One of the NASA study’s authors says it would take very expensive testing to determine how many plants would be needed to purify the air in an actual home. He typically recommends about 1 plant per 100ft2 as a best guess. His plant of choice is a golden pothos, or “devil’s ivy” since it’s easy to grow indoors.
The bottom line is that plants can help remove some indoor air contaminants, but… they won’t solve all your indoor air quality problems. Your first step to improve indoor air quality should always be to reduce contaminants at the source. This includes switching to non-toxic cleaners, skipping the fabric softener and dryer sheets, dusting more regularly, and installing a high-quality furnace filter – to name just a few simple strategies.
And if you’re seriously concerned about indoor air pollutants or allergens, you can consider investing in an air purifier. Not all are created equal, however, so you’ll want to make sure you do your research so you don’t end up wasting your money on something that does little more than a few houseplants would. You can check out my guide to air purifiers here.
I hope this helps settle your questions around using plants to reduce toxic chemicals from your home!