Improving Indoor Air Quality with Houseplants

Due to improved construction methods, buildings are better sealed to maximize energy efficiency. There is concern from some that these "sealed" buildings can trap VOCs (volatile organic compounds) gases, such as formaldehyde, polluting the indoor air. These air pollutants can cause problems for inhabitants, especially during the winter when people are forced to spend a great deal of time indoors.A variety of indoor plants

Houseplants have received a lot of attention as options for improving indoor air quality. In 1989, scientists from NASA discovered that plants could remove VOCs from the air inside sealed test chambers. While most of our homes are not sealed like the "biohome" that NASA created, everyone can benefit from the removal of VOCs, and this suggests that houseplants could help.

Since this study was released, dozens of plants like philodendron (Philodendron), peace lily (Spathiphyllum), and spider plant (Chlorophytum) have been suggested as houseplants to purify the air of gases like formaldehyde, benzene, xylene, toluene, ammonia, acetone, methyl alcohol, ethyl acetate, and trichloroethylene. Purportedly, the amount of purification depends on the plant being tested and different houseplants purify different toxic chemicals to differing degrees.

In reality, these houseplants have little effect on air quality in the home or office.  The NASA study put houseplants in small sealed chambers where they observed, after the injection of VOCs, a reduction in these chemicals at a slow rate.  Outside these very controlled conditions in our homes and office buildings, there is a constant turnover of air, even in the newest and most air-tight of buildings.  Combine that with the fact that additional VOCs are always being introduced, and it's not possible for houseplants (even a lot of them at one plant for every square foot) to effectively remove these volatile chemical toxins from the air.   

Several studies, including those done by the EPA, agree, stating, "There is currently no evidence that a reasonable number of houseplants remove significant quantities of pollutants in homes and offices.”  

This doesn't mean the scientists involved have been conducting bad research.  The NASA study isn't flawed.  The highly controlled testing environment of the study just doesn't directly translate to our "real world" conditions.  The dynamics of indoor air quality are far more complex, and when you take that into account, houseplants don't have an effect on the air quality indoors.

Of course, this also doesn't mean that you should toss out all your houseplants!  Indoor plants beautify the home and help you nurture a green thumb even in the dead of winter.  There are still many reasons to grow houseplants so buy that orchid or philodendron and enjoy it!

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Last reviewed:
January 2024