During the late ‘80s, NASA was searching for a way to detoxify the air in its space stations. So it directed a study to decide the best plants for filtering the air of toxic agents and converting carbon dioxide to oxygen. In 1989, when the results were published in a clean air study, a definitive list of the plants that are most effective at cleaning indoor air was also provided. The report also suggested having at least one plant per every hundred square feet of home or office space. According to NASA, the following plants are the best air-filtering houseplants:
1. Dwarf Date Palm
2. Boston Fern
3. Kimberly Queen Fern
4. Spider Plant
