SAFETY & INDOOR AIR QUALITY GUIDE
NASA Says These 10 Plants Purify Your Home's Air
Backed by NASA’s 1989 Clean Air Study — the honest guide to which houseplants actually clean the air you breathe, which ones are pet-safe, and how many you really need.
You walk into your bedroom after a long day, and the air feels… heavy. Stuffy, almost stale. It is not your imagination. The paint on your walls, the carpet under your feet, and even your furniture are quietly releasing chemicals into the air you breathe every single night.
Here is the good news: fixing this does not require an expensive air system or a home renovation. Back in 1989, NASA's Clean Air Study discovered that ordinary houseplants can absorb common indoor pollutants like formaldehyde, benzene, and xylene right through their leaves and roots. Since then, air purifying plants have become one of the simplest, most affordable upgrades you can make to your home.
In this guide, we will walk through the actual NASA-tested plants, which ones are safe for pets, how many you really need per room, and where the science gets honest about its limits — plus the plant-safety habits that keep the whole setup genuinely safe for your household.
What Is the NASA Clean Air Study, Really?
In the late 1980s, NASA needed a way to keep the air breathable inside sealed space stations. Working with the Associated Landscape Contractors of America, researcher Dr. B.C. Wolverton tested dozens of common houseplants in sealed chambers loaded with three toxic chemicals: formaldehyde, benzene, and trichloroethylene.
The results were impressive. Certain plants removed a significant share of these pollutants within 24 hours, working through both their leaves and the microorganisms living in their soil. That research became the foundation for almost every NASA air purifying plants list you will find online today, including this one.
But here is the part most articles skip: the study was conducted in sealed laboratory chambers, not in a normal room with doors, windows, and airflow. That matters for setting realistic expectations, which we cover honestly next.
Do Air Purifying Plants Really Work? An Honest Look
This is one of the most searched questions on the topic, and it deserves a straight answer. Plants absolutely do remove VOCs from the air — that part of the science is solid. What is exaggerated online is the scale.
NASA’s original test used one plant per 100 square feet in a sealed chamber. A real bedroom or living room is not sealed. Air moves in and out through doors, HVAC vents, and gaps around windows, diluting the effect. According to the EPA's research on indoor air quality, VOC concentrations indoors can run two to ten times higher than outdoors, coming from paint, furniture, cleaning products, and carpet.
So should you skip the plants? Not at all. Think of them as one honest layer in a bigger strategy — alongside good ventilation, low-VOC finishes, and a real air purifier if allergies are a serious concern. Plants add real, measurable benefit. They are just not a replacement for opening a window.
The Top 10 NASA-Approved Air Purifying Plants
These ten made NASA’s original list and remain the most reliable, widely available choices for homes today. Here is the full breakdown before we dig into each one individually.
| Plant | Removes | Light | Pet Safe? |
|---|---|---|---|
| Snake Plant | Formaldehyde, benzene, xylene | Low to bright | No |
| Peace Lily | Formaldehyde, benzene, ammonia | Low to medium | No |
| Spider Plant | Formaldehyde, xylene, CO | Low to bright | Yes |
| Pothos | Formaldehyde, benzene, xylene | Low to bright | No |
| English Ivy | Formaldehyde, benzene | Medium to bright | No |
| Areca Palm | Xylene, toluene | Bright indirect | Yes |
| Boston Fern | Formaldehyde, xylene | Medium to bright | Yes |
| Chinese Evergreen | Formaldehyde, benzene | Low to medium | No |
| Rubber Plant | Formaldehyde | Medium to bright | No |
| Dracaena | Formaldehyde, benzene, xylene | Low to bright | No |
1. Snake Plant — The Hardest to Kill
If you have ever killed a plant by accident, start here. Snake plant tolerates low light, irregular watering, and near-total neglect, while steadily filtering formaldehyde and benzene. It is also unusual for releasing oxygen at night, a popular pick for bedrooms.
2. Peace Lily — The Beautiful Multitasker
Peace lily earns its spot for tackling ammonia — common in cleaning products — alongside formaldehyde and benzene. Its white blooms droop dramatically when thirsty, telling you exactly when it needs water.
3. Spider Plant — The Pet-Safe Beginner Pick
Spider plant is one of the very few NASA-list plants genuinely non-toxic to cats and dogs, a favorite for family homes. It grows fast, produces baby “pups” you can propagate for free, and shrugs off low light.
4. Pothos — The Almost-Impossible-to-Kill Vine
Pothos, sometimes called money plant, trails beautifully from a shelf or hanging basket while removing formaldehyde, benzene, and xylene. It tolerates missed waterings better than almost anything — just keep it away from pets.
5. English Ivy — The Airborne Mold Fighter
English ivy is one of the few plants shown to also reduce airborne mold spores, in addition to formaldehyde and benzene. It prefers medium to bright light and does best trailing from a hanging basket.
6. Areca Palm — The Statement Air Purifier
Areca palm brings a lush, tropical look while filtering xylene and toluene, and adds humidity back into dry indoor air. It is pet-safe, making it great for a large, sunny living room corner.
7. Boston Fern — The Humidity Lover
Boston fern tackles formaldehyde and xylene while thriving in humid spots like bathrooms. It is fussier than the rest — it wants consistent moisture — but it is completely pet-safe.
8. Chinese Evergreen — The Low-Light Specialist
Few plants tolerate dim corners as gracefully as Chinese evergreen. It removes formaldehyde and benzene while adding striking variegated leaves to windowless offices or hallways.
9. Rubber Plant — The Bold Floor Statement
Rubber plant grows into a tall, glossy-leafed floor plant that quietly filters formaldehyde. Its large leaf surface area means more square footage for pollutant absorption.
10. Dracaena — The Easy-Care All-Rounder
Dracaena covers formaldehyde, benzene, and xylene in one hardy, low-maintenance package. With dozens of varieties in different heights, it fits almost any corner of your home.
A Few More Honorable Mentions
NASA’s list has grown since 1989 through follow-up research. Aloe vera earns a spot for pulling double duty — it filters air while also offering a soothing gel for minor burns. Bamboo palm is another strong pick for larger rooms, tackling the same VOCs as Areca palm. And ZZ plant, while not on the original NASA list, has become a favorite for its near-indestructible, low-light tolerance.
If you want something that fits a totally different care category, our long-life plants selector and dramatic thirsty plants guide round out the broader low-maintenance houseplants world — including a few succulents for beginners that overlap with this list, like aloe vera.
How Many Air Purifying Plants Do You Actually Need?
NASA’s original guidance suggested roughly one plant per 100 square feet for a measurable effect in a sealed environment. In a real, ventilated room, most experts recommend going a bit heavier — around two to three medium-sized plants per 100 square feet.
For an average 10×12 bedroom, that works out to two or three plants of varying sizes rather than one lonely pot on the windowsill. Mixing plant sizes helps too: a tall floor plant like rubber plant or dracaena adds more leaf surface area than several small pots combined.
Not sure how much room your containers actually need? Our pot size calculator and gallon pot size finder make it easy to match the right container to each plant as it grows.
Best Air Purifying Plants by Room
Different rooms have different light, humidity, and traffic patterns. Here is how to match the right plant to the right space.
Bedroom
Snake plant and peace lily are the top bedroom air purifying plants since both continue releasing oxygen overnight, supporting better sleep. Keep them on a nightstand or dresser where they get a bit of morning light.
Office or Desk
Pothos and Chinese evergreen handle low desk lighting and inconsistent watering better than almost anything else. A small ZZ plant works well too if you want something completely hands-off.
Bathroom
Boston fern and English ivy both love the humidity a bathroom naturally provides, which helps them do their best air-filtering work. Just make sure the room gets at least some indirect light.
Living Room & Small Apartments
A larger statement plant like Areca palm or rubber plant fills a bright corner beautifully. Tight on floor space? Hanging plants like pothos and English ivy trail from a shelf instead of taking up square footage.
Pet-Friendly Air Purifying Plants (Safe for Cats and Dogs)
Here is an uncomfortable truth the best-of lists rarely lead with: several of the most popular NASA-list plants are toxic to cats and dogs, including peace lily, pothos, English ivy, dracaena, and Chinese evergreen. Ingesting them typically causes mouth irritation, drooling, or vomiting.
| Plant | Pet Safety Status | What Happens If Ingested |
|---|---|---|
| Spider Plant | Safe for cats & dogs | Mild GI upset only, generally non-toxic |
| Areca Palm | Safe for cats & dogs | Non-toxic; safe even if chewed |
| Boston Fern | Safe for cats & dogs | Non-toxic; good bathroom choice for pet homes |
| Peace Lily | Toxic to cats & dogs | Oral irritation, drooling, vomiting |
| Pothos | Toxic to cats & dogs | Mouth and throat irritation, swelling |
| English Ivy | Toxic to cats & dogs | Vomiting, abdominal pain, diarrhea |
Low-Light and Beginner-Friendly Options
If your track record with plants is more “accidental cactus murder” than green thumb, start with snake plant, pothos, or ZZ plant. All three tolerate irregular watering, low light, and general neglect while still filtering the air.
For a full lineup of forgiving choices, browse our best indoor plants roundup and 25 moody houseplants for beginners.
Whatever you plant, the right soil matters just as much as the right species. Our soil type guide walks through drainage and mix basics so your new plant actually thrives.
Plants vs. Air Purifiers: Which One Actually Wins?
Being honest here matters more than being popular. A mechanical HEPA air purifier processes far more air volume per hour than any realistic number of houseplants you would fit in a room. If you have severe allergies or asthma, a purifier is the more effective tool.
Where plants win is everywhere else: they add humidity, reduce stress, look good, and cost a fraction of a purifier’s price. The smart approach is layering both alongside good ventilation for the healthiest result.
Plant Safety Guidelines Every Home Should Follow
Growing air-purifying plants is safe for most households — a few real habits keep it that way for kids, pets, and your own health too.
Peace lily, pothos, English ivy, dracaena, and Chinese evergreen are toxic if chewed or eaten. Place them out of reach or skip them entirely with curious toddlers or animals around.
Pothos, dracaena, and English ivy release a sap that can irritate skin or eyes on contact. Rinse hands after pruning or repotting.
Standing water in a cache pot or saucer becomes a breeding ground for mosquitoes and mold spores within a day or two.
Soggy soil is the single biggest cause of harmful mold growth in houseplants, which can worsen allergies rather than ease them.
A top-heavy rubber plant or dracaena in a lightweight pot can tip onto a child or pet. Use a wide, weighted base.
Spraying VOC-heavy products on a plant meant to remove VOCs defeats the purpose. Use a mild soap-and-water wipe instead.
ASPCA Animal Poison Control: (888) 426-4435. Poison Control (people): 1-800-222-1222.
Simple Care Tips to Keep Your Air Purifying Plants Thriving
- Water when the top inch of soil feels dry, not on a fixed schedule — overwatering kills more houseplants than neglect ever does.
- Wipe dust off leaves every few weeks. Dust blocks light absorption and slows a plant's ability to filter air.
- Repot every 12 to 18 months, or once roots start circling the pot. Our pot liter calculator helps you size the next container correctly.
- Group plants together loosely to raise ambient humidity — check our plant spacing calculator first so airflow stays healthy between pots.
- Watch for yellowing leaves, a common early warning sign of overwatering, poor light, or a nutrient issue worth catching early.
Air-Purifying Plants: Frequently Asked Questions
Bringing It All Together
Air-purifying plants will not replace ventilation or a real air purifier for serious concerns, but they are a genuine, low-cost upgrade to how your home feels and breathes. Start with one or two forgiving picks like snake plant or pothos, learn their rhythm, and expand from there.
Pick plants that match your light, your pets, and your patience level, and you will end up with a home that looks better and breathes cleaner — no renovation required. Follow the safety habits above, and clean-air greenery becomes a genuine upgrade with none of the avoidable downsides.
