The spider plant (Chlorophytum comosum) is a recognized and easy-to-grow houseplant, distinguished by its arching, striped leaves and the small plantlets that dangle from its stems. For decades, this resilient plant has been marketed not just for its decorative appeal, but also as an effective, natural air purifier. This belief stems from scientific findings suggesting the spider plant can help clean the air in our homes. This article explores the science behind the purification claim and its actual impact on the typical indoor environment.
Addressing the Air Purification Claim
The direct answer is that spider plants technically absorb some airborne contaminants. Under controlled conditions, the plant has demonstrated the capacity to filter out certain chemical compounds. This ability is a natural physiological process that all plants possess to varying degrees. While the claim is rooted in scientific fact, the technical truth is often misunderstood regarding the scale and significance of the effect in a typical home. The real-world impact is much smaller than marketing suggests.
The Science Behind Pollutant Removal
The concept of using houseplants to clean indoor air was popularized by the 1989 NASA Clean Air Study. This research investigated ways to purify the air in sealed environments, such as space stations, and showed that certain plants could process Volatile Organic Compounds (VOCs). Spider plants were tested and found effective at removing specific pollutants, including formaldehyde (from furniture and cleaning products) and xylene (often found in paints and adhesives).
The purification mechanism, known as phytoremediation, involves the plant absorbing airborne toxins through its leaves and roots. A significant portion of this process occurs in the root-soil zone, where microorganisms play a fundamental role. These soil microbes actively break down and metabolize the absorbed VOCs into less harmful substances. The plant acts as a delivery system, transporting pollutants from the air to the soil where the microbial community performs the detoxification.
Real-World Effectiveness in Indoor Spaces
The laboratory results from the NASA study were compelling, but they were conducted in small, sealed chambers—a controlled environment very different from a typical home. In these tightly controlled conditions, spider plants removed a high percentage of pollutants over 24 hours. A real living space involves a much larger volume of air and constant air exchange with the outdoors through ventilation systems.
Research attempting to replicate these effects in real-world settings found that the air cleaning rate by a few houseplants is negligible compared to standard ventilation. To match the air purification rate of a typical building air exchange, estimates suggest needing between 10 and 1,000 plants per square meter. Therefore, while a spider plant actively works to clean the air, a small collection will not significantly reduce the overall concentration of indoor VOCs. Plants should be appreciated for their aesthetic and psychological benefits, not relied upon as a primary method for improving air quality.