From snake plants to ferns, much of the greenery that adorns living rooms and kitchens is marketed as air-purifying. However, scientists largely agree that vegetation can’t do very much to clean an entire room. Now, a Parisian start-up known as Neoplants is trying to change that—by growing genetically modified plants that filter harmful chemicals out of the air.
“For too long, the advance of technology has been at the expense of our environment,” says Lionel Mora, Neoplants CEO and co-founder, in a statement. “Our team views nature as the world’s most powerful technology. It is critical that we use human talent for innovation to partner with and enhance our natural world rather than consuming it.”
Its first product, called the Neo P1, is a bioengineered version of the pothos houseplant—also known as devil’s ivy—which is characterized by its leafy green vines. Because it is relatively easy to care for, pothos is a popular choice for people looking to spruce up their living spaces. But the Neo P1 starts at $179—roughly five to ten times the price of a normal pothos. And to purchase one, prospective shoppers must first join a waitlist.
That’s because the Neo P1 is meant to capture and recycle dangerous air pollutants commonly found in homes called volatile organic compounds (VOCs)—namely formaldehyde, benzene, toluene and xylene. These are often human-made chemicals in paints, aerosol sprays, wood preservatives and automotive products, among other sources. Concentrations of VOCs are consistently higher indoors than outdoors.
Genetic adjustments to the Neo P1 enable the houseplant to process these chemicals into substances like carbon dioxide, which it can then use to keep growing. And bacteria in the soil, enriched with the common gardening additive biochar, also convert VOCs into less harmful products, such as sugars.
These groups of microorganisms, however, “are very difficult to maintain,” says Jennifer Brophy, a researcher developing genetically modifed plants at Stanford University who is not involved with Neoplants, to MIT Technology Review’s Claire L. Evans. “As soon as you ship a product to somebody, the viability of these bacteria declines.” To remedy this, each Neoplant is sold with a three-pack of “Power Drops,” which are bacteria that help the plant continue to metabolize VOCs.
But when it comes to proving the Neo P1’s efficacy, “things get thorny,” writes Wired’s Will Pritchard. The idea of air-purifying plants comes largely from a 1989 study by NASA and the Associated Landscape Contractors of America, in which regular houseplants were tested in two-by-two-foot chambers. When scientists filled these little rooms with VOCs, they found the plants could absorb some of the harmful compounds.
However, those results can be misleading, as Michael Waring, an environmental engineer at Drexel University who is not involved with Neoplants, told National Geographic’s Sarah Gibbens in 2019. The problem with those experiments, Waring explained, is that the densely gaseous chambers in labs did not accurately mimic the typical household or office environment where these plants would be.
In actuality, it would take around ten houseplants per square foot to noticeably improve air quality, Waring and others reported in a 2019 study. That means a 100 square foot bedroom would need around 1,000 plants.
“Plants, though they do remove VOCs, remove them at such a slow rate that they can’t compete with the air exchange mechanisms already happening in buildings,” Waring told National Geographic.
As for Neoplants, its Neo P1 was tested in a similar chamber—a 35-liter glass compartment. In it, the Neo P1’s results were 30 times better than NASA’s, according to the company—which means it would still take a massive amount of them to clean a room. While the company is continuing trials, field testing has not produced reliable results. But engineers are designing testing sites that more accurately resemble living spaces.
“We see bioengineering as a way of empowering nature to evolve alongside human technology,” says Patrick Torbey, the company’s chief technology officer, in the statement. “Our team is committed to building a green and vibrant future here on Earth, where plants are upgraded as frequently as our phones, where people can see and feel the benefits of nature as clearly as any piece of technology.”
Bioengineered plants aren’t exactly new—other companies are using altered greenery to try and suck up more carbon dioxide from the atmosphere. In February, poplar trees designed by the start-up Living Carbon took root in Georgia in what might have been the first planting of genetically modified trees in a U.S. forest. And researchers at the University of Wisconsin–Madison have experimented with mutated mustard plants that do the same thing.
To Neoplants executives, cleaning the air inside a home is a more logical starting point than trying to filter the entire atmosphere. But that hasn’t stopped them from dreaming big about the future. As Torbey tells MIT Technology Review, “I’ll be disappointed if there’s a plant on the moon and it’s not a Neoplant.”