Humble houseplants that filter air

houseplants that filter airWe know the value of bringing plants into a home to add color and life. What we may not realize is how important it is to choose houseplants that filter air. Apart from being attractive and helping to bring a bit of the outdoors inside, they filter out harmful chemicals found in the air.

NASA conducted a clean air study in 1989 because they wanted to find ways to clean air in space stations. As a result of this research, they compiled a list of air-filtering plants.  These plants do not just absorb carbon dioxide and release oxygen but also eliminate certain harmful chemicals from the air.

What is in our household air?

Formaldehyde is one of the chemicals found in household air. It is found in the glues that hold furniture together, caulks and sealants, carpet glues and paints. It is also found in table napkins, synthetic fibers, paper towels, facial tissues and waxed paper. It is even emitted from water-and-stain repellant finishes on upholstery.

Benzine is another culprit. It evaporates into the air very quickly and is found in glue, paint, furniture wax, dyes, detergents, and some plastics. It can be emitted from gas ranges too and is also found in tobacco smoke.

Xylene is used widely as a solvent in the rubber, leather, paint and printing industries, so it is also found in the air we breathe indoors.

Trichloroethylene is used as an ingredient in adhesives, paint removers/strippers, varnishes, some paints and printing inks.

The effects of exposure to these harmful chemicals depend on the level of exposure, how it occurs and how long it lasts. It is unlikely that you will be exposed to high levels of these chemicals in your household air but there is no question that exposure can cause health problems.

Adverse health effects

If you are subject to asthma, allergies or auto-immune disorders, you will naturally wish to take all the measures you possibly can to make the air you breathe as clean as possible. The chemicals mentioned above all have irritant effects.

Formaldehyde is normally present at low levels in both indoor and outdoor air. However, when it is present in the air at higher levels, it starts to create problems like watery eyes, coughing, wheezing, skin irritation, burning of eyes, and nausea. Some people are more sensitive to its effect than others.

Benzene can cause some serious health issues if people are exposed to high levels for long enough. They may become drowsy, dizzy and have headaches, tremors, and confusion. Long-term exposure disrupts normal blood production and can result in leukemia.

The main effects of inhaling xylene are symptoms such as dizziness, nausea,  headaches, and vomiting. Long-term exposure may lead to symptoms such as depression, insomnia, tremors, impaired concentration, and even short-term memory issues.

Exposure to moderate amounts of trichloroethylene may cause headaches, dizziness, and sleepiness.

Although minimal exposure to these chemicals may not cause severe health problems, it still produces symptoms that seriously affect a person’s wellbeing.

5 tips for choosing indoor plants

Dr. Wolverton, in his book How to Grow Fresh Air,  based on the results of the research done in the NASA study, shows how to grow and nurture 50 air-filtering plants. Here are some suggestions on how to go about narrowing down your selection and choosing what you need for your home.

  • Think about where you want to place plants and then see how much sun the area receives. Is it direct or indirect sunlight?  Is there very little light at all?  Plants that can survive inside are usually from tropical or subtropical climates where they are used to growing in dappled light. Their leaves are adapted to photosynthesize well under such conditions.
  • Think about which plants will suit your decor.  Sculptural plants like the Madagascar dragon tree or a palm go well in modern interiors.  On the other hand, if your look is more farmhouse or cottage, you will do better with softer, more romantic plants like ferns.
  • Think about how much experience you already have with caring for indoor plants. If you do not have much experience, it is better to start with one of the varieties that is hardier and less likely to suffer from your inexperience.
  • Think about grouping various plants together. They often make more of a statement when grouped together and are also easier to care for.
  • Think about how many you are going to need to be effective in a room. The NASA research suggests choosing one 10 to 12-inch potted plant per 100 square foot of space.  This means that if your home is 2,000 square foot, you will need about 20 plants.

9 of the best air-filtering plants

The Peace Lily

peace lilyThese are common household plants because they grow easily. They can become quite tall and produce white flowers.  They prefer moderate temperatures and indirect light.  Their high transpiration rate helps to humidify the air.

Keep their soil moist at all times but be careful not to over-water.

They filter out a range of chemicals, including formaldehyde, benzene,  ammonia and trichloroethylene.

They also help to remove mold spores so they are especially suited for bathrooms, kitchens and laundry rooms.


Golden Pothos

Golden PothosThese plants are extremely forgiving. If you don’t have ‘green fingers’, they are probably one of the best starter plants to buy.

They are hardy, grow quickly and their vine-like stems make them suitable for putting in a hanging basket.

They enjoy cool temperatures and low levels of sunlight.

They may not be quite as effective as the Peace Lily at filtering out a wide range of pollutants but they make the NASA list as one of the top three plants for filtering out formaldehyde.

Spider plant

spider plantThey have vibrant green and white stripes and grow long stems with small spider clumps that you can break off and plant in a new pot. They grow very easily and love bright indirect sunlight.

Although they are easy to grow, it is important for them to stay moist.

They are one of the top three plants for filtering out formaldehyde and also remove xylene.

Boston Fern

Boston fernWith its frilly leaves and long, hanging fronds, the Boston fern is a popular choice as an indoor plant.

These ferns are fond of lots of indirect light and humidity. They are not difficult to care for but they do need to stay moist.

They need to be watered more frequently in the hottest months and will lose their healthy green color if they become too dry.

They remove  formaldehyde and xylene from the air.

Snake Plant

snake plant Snake Plants are also known as ‘mother-in-laws tongue’. They are easy to grow and can tolerate a bit of neglect!

They do not need much water to survive.

They  absorb carbon dioxide and release oxygen during the night, so they are good plants to have in the bedroom. This is why these plants are also known as “the bedroom plant”.

They effectively remove benzene, formaldehyde, trichloroethylene and xylene from the air.

 Bamboo Palm

bamboo palmThis is one of the most popular palms in the world. These palms are attractive and  easy to care for.

They like shade, indirect sunlight and they need to be well-watered.

These plants filter out formaldehyde and xylene.

They are also safe for animals, unlike many of the others on this list, and are particularly liked by cat lovers.

English Ivy

English IvyThese everygreen climbers are easily grown in hanging baskets. They are a good choice for low light and grow best with moist soil.

They are very invasive so they work better as potted plants.

They remove formaldehyde, benzene, zylene and trichloroethylene from the air.

There was a study done that showed that they reduce airborne fecal-matter particles and allergens like mold.


Rubber Plant

rubber plantThey have broad, dark green shiny leaves and are one of the easiest plants to grow. They thrive even in dim lighting.

Common mistakes are to over-water or to move the plants around too much. It is important to keep them away from cold and drafts in winter.

You will need to keep the soil lightly to moderately moist and to make sure the water drains well.

They remove formaldyhide from the air.


Madagascar dragon treeThis group of plants offers many different shapes, colors, and sizes. They also flourish in different light conditions.

They like soil to be damp but not soggy.

They filter out formaldehyde, benzene, xylene, and trichloroethylene.




Caring for your indoor plants

  • Make sure they have the right amount of sunlight.
  • Make note of the water requirements and do not over or under-water.
  • Periodically dust leaves with a damp cloth to ensure that they absorb pollutants most effectively.
  • Avoid synthetic fertilizer and rather use compost.
  • Capture rainwater for watering them if possible.


It is possible to create a more pleasant and healthier environment indoors with the use of specific plants. Remember that plants are like the lungs of the earth and they add moisture and filter out toxins. They bring the outside in and make our enclosed spaces livable, preventing sick building syndrome and giving us fresher air to breathe.






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