Are Air Purifying Plants a Myth?

home space with bookshelf filled with house plants

There are many reasons to have indoor plants in your home, but do they really purify the air? We’ll take a look at the some of the speculation surrounding air-purifying plants, and whether or not they can reduce allergies, and combat household pollutants.

Plants as Air-purifiers

Back in 1989, NASA did a study that reported certain plants were excellent at removing toxins and purifying the air. They knew the synthetic materials used to construct their test-lab were “off-gassing” aka, spreading low level chemicals into the air—and that these same chemicals were found in households.

The study then found that in conjunction with carbon filters, many indoor plants were really great at removing these toxins. Volatile organic compounds, or “VOC’s”, like formaldehyde, benzene, and trichloroethylene were either lowered, or completely eradicated by your everyday run of the mill houseplants. Pretty exciting stuff!

happy woman reading in a chair in a bright room with large hanging house plants

Findings Published

One of the scientists involved with the NASA studies was Bill Wolverton, who published his findings in a book called, “How to Grow Fresh Air: 50 Houseplants That Purify Your Home or Office.” All of a sudden golden pothos, peace lilies, dragon trees, dracaenas, snake plants, mums, and gerbera daisies were green-sprout-superheroes armed with the ability to remove all three of the harmful toxins, and highly recommended as additions to your indoor space. The extensive list of plants gave people a new reason to want them around for their amazing air-purifying ability, and is still a common reason why people purchase plants today.

The Problem

It’s not that NASA lied or that the study was debunked—these plants really are quite wonderful at removing toxins; however, they are wonderful at removing them in a completely airtight space such as a spaceship, or the test-lab NASA used. Over the years, plant-lovers and article-writers have cherry-picked the information without considering the very large environmental differences between a spaceship and your home or office. No matter how well your house is built, there is still an influx of fresh air that comes and goes through the various envelopes of the structure. Your home breathes, and that’s a good thing!

bright white room with furniture and house plants

How Many Plants Would You Need?

Surely some of you are thinking that maybe you have enough plants to make it worthwhile, right... RIGHT?!? Well, there are folks who have done the calculating for you, and found that you would need approximately 10 plants per square foot of typical home or office space to reap the benefits of what the NASA scientists reported.

Even with the very best VOC-sucking plants in every nook and cranny of your home, the air in your house turns completely over once every hour, meaning the plants don’t get a chance to do their thing. In terms of adding oxygen to the air, the amount is negligible—yes, O2 is added, but it’s in such small amounts that out bodies don’t even notice.

bright stylish home space with house plants

Proper Plant Care is More Important

On the flip side, plants can actually exacerbate allergy symptoms if they aren’t taken care of properly. One of the things that can cause allergies to worsen is dust collection and mold. Many plant owners forget to dust their foliage, especially in the winter months when HVAC systems are sending particles airborne. Use a damp towel to collect build-up once a week, gently drawing away particles from the stems towards the tips of leaves. Blooms generally don't need dusting since they don’t last very long and would be prone to surface damage.

Also, allow your plants’ soil to dry out between waterings, as excess moisture is a haven for mold and fungus growth. Check that the soil is dry to the touch and not just on the surface, but approximately an inch deep. Of course, some house plants have different water needs (succulents want even less water than average, ferns want more), but this is a good rule of thumb for most indoor plants.

happy family on couch with house plants

Other Benefits DO Exist!

Keeping plants happy and healthy does provide home owners and office workers with extensive health benefits, even if it isn’t improved air breathing quality. Some plants might be able to reduce humidity, cutting down the hazards of mildew and mold.

Moreover, many studies have shown that the mere presence of plants can eradicate stress and make people feel calmer and happier. Having a little bit of nature in your space has a proven positive effect on most people by increasing energy levels, boosting overall mood, even supporting cognition and health.

Interior decorators almost always include plants in their design for good reason—the addition of greenery is an inexpensive and easy way to spruce up your home or office décor.

The bottom line is, unless you live in a hermetically sealed lab, or are an astronaut living in space, your indoor plants aren’t significantly purifying the air around you—but that doesn’t mean they aren’t benefiting you in many other ways. Whether in outer space or here on earth, plants are amazing companions to have and behold, just as they are.