In September 1989, the U.S. federal government’s National Aeronautics and Space Administration (NASA) released a report, Interior Landscape Plants for Indoor Air Pollution Abatement.
This followed extensive research in collaboration with the Associated Landscape Contractors of America (ALCA) about “sick building syndrome” and the ability of plants to reverse it. They found that oxygen-producing houseplants that have activated carbon plant filters and need low light have the potential to improve indoor air quality.
Plants convert carbon dioxide into fresh oxygen, which is how they remove toxins from the air. So, technically all indoor plants produce oxygen to some extent. But we’re going to look at the indoor plants that NASA lists. They include some very common oxygen-producing houseplants from the tall snake plant to the peace lily.
Do indoor plants increase oxygen?
If you scour the internet for answers you’ll find lots of research reports and posts that say indoor plants release oxygen. The importance of this is that by increasing oxygen in the air, plants remove harmful chemicals and toxins from the air.
But you’ll also find a surprising number of posts and research reports that state this is nonsense.
So who do you believe? Our advice is to read the evidence and weigh it up for yourself.
If you are a believer it will be because many scientists tell us that plants – and not just indoor plants – do increase oxygen. So do the scientists who undertook the two-year study supported by NASA.
Also, the U.S. Department of Agriculture (USDA) has long lauded the fact that trees are superheroes because of their role in increasing oxygen. The USDA Forestry Service fundis say:
“A tree has the ability to provide an essential of life for all living things on our planet – oxygen, and the power to remove harmful gasses like carbon dioxide making the air we breathe healthier.”
While they aren’t indoor plants, trees are plants, and all plants rely on photosynthesis to survive and thrive.
As the USDA explains, during the photosynthesis process, plants pull in carbon dioxide and water. Then they use energy from the sun to convert carbon dioxide into food for the plants.
The important by-product of this process is the oxygen the trees produce and release. Plants use oxygen to break down carbohydrates into energy. But they don’t need all the oxygen they produce.
14+ Indoor Oxygen Producing Plants
Even the cynics admit that indoor plants produce oxygen. But they argue that it’s impossible to detect how much oxygen an indoor plant produces.
Many insist that oxygen-producing houseplants don’t improve the quality of indoor air.
We are going to focus on the oxygen-producing houseplants identified by NASA. While they don’t state how much oxygen these plants produce, they do identify which volatile organic chemicals each of the plants is able to remove from the air.
The chemicals used to screen the plants were:
- Benzene
- Trichloroethylene
- Formaldehyde
All are known to be severe health risks to humans. They undertook tests using sealed experimental chambers for 24-hour exposure periods
The plants tested came from nurseries and they were kept in their original pots and potting soil for the study. This list is alphabetical.
Aloe Vera
Aloe vera is an intriguing succulent plant that grows wild in many sub-tropical, tropical, and arid climates worldwide. It is recognized globally as a medicinal plant that is particularly beneficial for our skin.
It grows best outdoors in USDA zones 9 and 10 but will thrive indoors if grown in a bright position that gets lots of indirect light.
Aloe vera isn’t as efficient as other plants in removing toxins. It is mentioned as removing relatively small amounts of formaldehyde, which pollutes just about all indoor environments.
Bamboo Palm
The bamboo palm, Chamaedorea seifritzii, is a small palm tree native to the rainforests of Guatemala and southern Mexico. Unlike other palm trees, it grows well indoors in low-light conditions.
The Areca palm, Dypsis lutescens, is also known as bamboo palm but is native to Madagascar. It doesn’t feature in NASA’s clean air study but is probably as effective as Chamaedorea seifritzii.
Chamaedorea seifritzii removed a considerable amount of trichloroethylene and benzene from the air. It removed by far the most formaldehyde of all the plants tested.
Banana
The banana, Musa oriana, is native to tropical areas including southeastern Asia. It’s one of the best Musa species to grow as a houseplant, but it’s not going to produce fruit indoors.
The NASA study found the banana to be relatively efficient in removing formaldehyde. But the bamboo palm removed more than 6½ times as much!
This probably indicates that bamboo palms produce more oxygen than banana plants.
Chinese Evergreen
The Chinese evergreen, Aglonema modestum, is native to subtropical and tropical parts of Asia. It’s become a popular houseplant because it grows in low light and doesn’t need much maintenance.
The NASA study used Aglonema modestum Silver Queen, which has lovely silvery variegated foliage. It featured a plant that was able to remove relatively small volumes of benzene.
Mass Cane, Janet Craig, Marginata, and Warnecki
All these plants produce oxygen and remove varying volumes of toxins. They are all types of Dracaena that are popular houseplants that are known for increasing oxygen levels indoors.
These types will grow from 6 feet to 10 feet tall in pots.
Mass cane, Dracaena massangeana, also known as corn plant or corn cane, is native to many tropical areas in Africa. It’s been popular as a houseplant in Europe for centuries, and since the early 20th century in the U.S. It proved fairly effective in removing trichloroethylene.
Dracaena deremensis Janet Craig was found to remove nearly double the amount of trichloroethylene. It was also effective in removing benzene, and even more so when it came to formaldehyde. It removed 77.6% of benzene in the experimental chambers.
Dracaena Marginata also removed all three chemicals. It was more effective than Janet Craig for trichloroethylene and benzene, but less effective for formaldehyde.
Dracaena deremensis Warnecki removed a greater volume of benzene than the other Dracaenas (70%). But it was less effective than Janet Craig when removing trichloroethylene – 20.2% vs 17.5%. It didn’t rank for formaldehyde.
Elephant Ear, Heart Leaf, and Lacy Tree Philodendron
Philodendrons come from Columbia, the Caribbean, and Venezuela. There are hundreds of species, a handful of which are commonly grown as houseplants.
Philodendron domesticum (elephant ear), Philodendron selloum (lacy tree), and Philodendron oxycardium (heart leaf) all removed quite low levels of formaldehyde. Presumably, this means they produce oxygen at levels as high as most other plants tested.
English Ivy
English ivy, Hedera helix, is a ubiquitous, fast-growing climbing plant native to Western Asia and many parts of Europe. It is also a common houseplant that looks good in hanging pots and baskets.
The NASA study, removed relatively low levels of all three chemicals, except for benzene. In fact, it removed the highest percentage (89.8) of benzene.
Ficus
Ficus benjamina, commonly known as weeping fig, is a common indoor plant of Asian origin. It is also grown in gardens that have enough space. In pots, it generally grows to between 3 and 5 feet. In the ground, it can grow up to about 50 feet.
These indoor plants removed small volumes of all three chemicals.
Gerbera Daisy
The Gerbera Daisy, Gerbera jamesonii, is native to South Africa and is grown in gardens all over the world. Beautifully ornamental, it is also kept as a pot plant indoors and is valued as a cut flower.
Of all the indoor plants tested, it removed the most benzene and trichloroethylene from the air.
Golden Pothos
Golden pothos, Scindapsus aureus, is native to southeastern Asia but grows happily indoors anywhere. It looks great in hanging baskets.
It removed a high percentage (73.2) of benzene but only about 9.2% of trichloroethylene from the experimental chambers. It also removed a relatively low volume of formaldehyde.
Green Spider Plant
The green spider plant, Chlorophytum elatum, which is native to parts of South Africa, is a popular houseplant worldwide.
It removed a reasonable volume of formaldehyde in the NASA tests.
Peace Lily
Peace lilies are native to the tropical rainforests of Columbia and Venezuela. Spathiphyllum Mauna Loa was chosen for the NASA tests.
It was one of the most successful plants to remove trichloroethylene and relatively successful for formaldehyde. It also removed quite a high volume of benzene.
Pot Mum
Exotic pot mums, Chrysanthemum morifolium, originate from Asia. Colorful and pot-hardy, they make great indoor plants.
Pot mums removed quite high percentages of toxins in the tests: 61% formaldehyde and 41.2% trichloroethylene. It was the second most successful plant, after the Gerbera daisy, in removing benzene from the air – 53% vs 67.7%.
Mother-in-law’s Tongue
Often referred to as the snake plant, Sansevieria laurentii, mother-in-law’s tongue is native to parts of tropical Africa. In 2017 (long after the NASA study) it was reclassified as Dracaena trifasciata, even though it looks very different from the dracaena plants we talked about earlier.
It successfully removed quite decent levels of all three chemicals, including 52.6% of the benzene in the air of the chambers.
Conclusion
Many indoor plants produce oxygen in sufficient volumes to cleanse the air in our homes.
Those we have listed were identified by NASA in its classic study of how oxygen-producing houseplants are able to cleanse the air. You will notice that even when the same species of plants, like Dracaena, were tested, different types produced different results. So you can’t generalize.