NASA compiles list of best plants to clean indoor air

A Note About the NASA Plant Study

The famous NASA Clean Air Study demonstrated that certain houseplants could remove volatile organic compounds (VOCs) in confined spaces such as homes, offices, and commercial buildings.

However, more recent research suggests that while plants can contribute to a healthier indoor environment and improve well-being, a typical number of houseplants alone is not the only answer. 

For the best results, combine healthy ventilation, source control, indoor air quality monitoring and houseplants. According to the U.S. Environmental Protection Agency (EPA), indoor air can be significantly more polluted than outdoor air, making ventilation and source control important for maintaining a healthy home.

We highlight the best plants and air quality solutions below.

Do Houseplants Really Improve Indoor Air Quality?

Based on the use of common indoor plants for indoor air purification, NASA studied about a dozen popular varieties of ornamental plants to determine their effectiveness in removing several key pollutants associated with indoor air pollution.

NASA research also found that living plants are so efficient at absorbing contaminants in the air that some will be launched into space as part of the biological life support system aboard future orbiting space stations.

Best Plants for Indoor Air Quality (NASA recommended)

1. Spider Plant (Chlorophytum comosum)

• Benefits: Known for its ability to remove formaldehyde, xylene, and toluene.
• Care: Easy to care for, thrives in indirect sunlight, and tolerates a range of temperatures.

2. Snake Plant (Sansevieria trifasciata)

• Benefits: Effective at removing formaldehyde, benzene, xylene, toluene, and nitrogen oxides.
• Care: Low-maintenance, tolerates low light, and infrequent watering.

3. Peace Lily (Spathiphyllum)

• Benefits: Removes formaldehyde, benzene, trichloroethylene, xylene, and ammonia.
• Care: Prefers indirect light and consistently moist soil.

4. Aloe Vera (Aloe barbadensis miller)

• Benefits: Known for removing formaldehyde and benzene.
• Care: Needs bright, indirect sunlight and infrequent watering.

5. Boston Fern (Nephrolepis exaltata)

• Benefits: Removes formaldehyde and xylene.
• Care: Prefers high humidity, indirect light, and regular watering.

6. English Ivy (Hedera helix)

• Benefits: Effective at removing formaldehyde, benzene, xylene, and toluene.
• Care: Thrives in moderate light and prefers moist soil.

7. Rubber Plant (Ficus elastica)

• Benefits: Known for removing formaldehyde.
• Care: Prefers bright, indirect light and moderate watering.

8. Golden Pothos (Epipremnum aureum)

• Benefits: Removes formaldehyde, benzene, xylene, and toluene.
• Care: Very easy to care for, tolerates low light, and infrequent watering.

9. Bamboo Palm (Chamaedorea seifrizii)

• Benefits: Effective at removing formaldehyde, benzene, trichloroethylene, and xylene.
• Care: Prefers indirect light and regular watering.

10. Dracaena (Dracaena spp.)

• Benefits: Removes formaldehyde, benzene, trichloroethylene, xylene, and toluene.
• Care: Prefers bright, indirect light and moist soil.

11. Areca Palm (Dypsis lutescens)

• Benefits: Removes formaldehyde, xylene, and toluene.
• Care: Prefers bright, indirect light and regular watering.

12. Gerbera Daisy (Gerbera jamesonii)

• Benefits: Known for removing benzene and trichloroethylene.
• Care: Needs bright light and well-drained soil.

13. Philodendron (Philodendron spp.)

• Benefits: Effective at removing formaldehyde.
• Care: Prefers indirect light and regular watering.

14. Weeping Fig (Ficus benjamina)

• Benefits: Removes formaldehyde, xylene, and toluene.
• Care: Prefers bright, indirect light and regular watering.

15. Chinese Evergreen (Aglaonema)

• Benefits: Known for removing formaldehyde and benzene.
• Care: Tolerates low light and infrequent watering.

What Pollutants Do Indoor Plants Help Remove?

Plants vs. Air Purifiers: Which is Better?

While neither are a complete replacement for the other. Plants and air purifiers both contribute to improving indoor air quality, but they work in different ways and have unique advantages and limitations.

Here’s a comparison of both:

Plant Provide:

• • Biological Processes: Plants naturally filter the air through photosynthesis and transpiration, removing pollutants like formaldehyde, benzene, and trichloroethylene.
  • Aesthetic and Psychological Benefits: Plants enhance the aesthetic appeal of a space and can reduce stress and improve mood.
  • Humidity Regulation: Plants can increase humidity in a dry environment, which can be beneficial for respiratory health.
  • Energy Efficiency: Plants require no electricity and are environmentally friendly.
  • Cost-Effective: After the initial purchase, plants have minimal ongoing costs.

Air Purifiers Provide:

• Pollutant Removal: Air purifiers with HEPA filters can remove up to 99.97% of airborne particles, including dust, pollen, mold spores, and pet dander.
• Odor and Chemical Absorption: Activated carbon filters in air purifiers can effectively remove odors and volatile organic compounds (VOCs).

Combined Approach

For optimal indoor air quality, a combined approach using both plants and air purifiers can be highly effective:

• Plants: Use plants to naturally improve air quality, add humidity, and enhance the aesthetic appeal of the space.
• Air Purifiers: Use air purifiers to quickly and efficiently remove a wide range of pollutants, including particulates, VOCs, and allergens.

While more research is needed, Dr. Bill Wolverton, formerly a senior research scientist at NASA’s John C. Stennis Space Center said “We feel that future results will provide an even stronger argument that common indoor landscaping plants can be a very effective part of a system used to provide pollution free homes and work places.”

How else can you improve indoor air quality at home?

While plants are effective for adding humidity and removing pollutants, you can also take these steps to improve your indoor air quality further:

1. Regularly ventilate your home by opening windows (when weather permits)
2. Use exhaust fans in kitchens and bathrooms to remove moisture and contaminants
3. Avoid using harsh chemicals for cleaning and opt for non-toxic alternatives
4. Use a dedicated indoor air quality monitor to track real-time air quality (see the latest case study)

Choosing the Right Indoor Air Quality Solutions

By incorporating these plants into your indoor environment, you can significantly improve air quality, reduce pollutants, and create a healthier living space. Additionally, these plants can enhance the aesthetic appeal and provide a sense of well-being.

Houseplants can contribute to a healthier indoor environment, but they cannot tell you when indoor air quality begins to decline.

An indoor air quality monitor provides real-time visibility into:

• Carbon dioxide (CO₂)
• Temperature
• Relative humidity
• Indoor comfort conditions

The CM-INK-1 Wireless Indoor Air Quality Monitor helps homeowners, classrooms, offices, and hobbyists understand exactly what's happening inside their indoor environment so they can make informed decisions about ventilation and comfort.

Combining healthy houseplants with real-time indoor air quality monitoring creates a more complete approach to maintaining a healthy indoor space.

For more information, check out this complete list of plants you can use to clean your indoor air. Or watch this great video (5 minutes) about a gentleman who uses plants to grow his own fresh air.

Frequently Asked Questions about Indoor Air Quality and Houseplants

What causes poor indoor air quality inside a home?

Indoor air quality can be affected by everyday activities and common household materials. Cooking, cleaning products, furniture, paints, pet dander, dust, mold, poor ventilation, combustion appliances, and elevated carbon dioxide (CO₂) levels can all contribute to reduced indoor air quality, making regular ventilation and monitoring important for maintaining a healthy home.

How can I tell if my indoor air quality is poor?

Many indoor air pollutants cannot be seen or smelled, making them difficult to detect without monitoring equipment. Signs of poor indoor air quality may include headaches, fatigue, allergy symptoms, stale air, excessive humidity, or elevated CO₂ levels. An indoor air quality monitor can provide real-time information about environmental conditions so you know when improvements such as increased ventilation may be needed.

Can houseplants reduce carbon dioxide (CO2) indoors?

Plants naturally absorb carbon dioxide (CO2) during photosynthesis, but the amount removed by a typical collection of houseplants is relatively small compared to the amount of CO2generated by people inside a home or office. If you're concerned about elevated CO2 levels, improving ventilation and using a reliable indoor air quality monitor are much more effective ways to assess and manage indoor air quality.

Are air purifiers better than houseplants?

Houseplants and air purifiers serve different purposes and work best together rather than replacing one another. Air purifiers equipped with HEPA and activated carbon filters can quickly remove airborne particles, allergens, smoke, and some VOCs, while plants provide natural beauty, modest humidity benefits, and contribute to a more comfortable indoor environment.

How many houseplants do you need to improve indoor air quality?

There is no universally accepted number of houseplants needed to significantly improve indoor air quality in a typical home. While the NASA study was conducted in small sealed chambers, modern research suggests that achieving measurable pollutant removal in real-world spaces would require far more plants than most people keep indoors. Even so, adding several healthy plants can still contribute to a more pleasant and inviting living environment.

Which indoor plants are safest for pets?

If you have cats or dogs, it's important to choose non-toxic houseplants. Pet-friendly options include Spider Plants, Areca Palms, Boston Ferns, Parlor Palms, Calatheas, and many Peperomia varieties. Before bringing any new plant into your home, always verify its safety with your veterinarian or trusted resources such as the ASPCA's toxic and non-toxic plant database.

What is the best houseplant for improving indoor air quality?

There isn't a single "best" plant because each species has unique characteristics and care requirements. Spider Plants, Snake Plants, Peace Lilies, and Golden Pothos consistently rank among the most popular choices because they are easy to maintain, adaptable to indoor environments, and were among the plants highlighted in NASA's research on indoor air purification.