evidence: "According to NASA's Clean Air Study, the snake plant is so effective in producing oxygen that if you were locked in a sealed room with no airflow, you would be able to survive with just 6-8 plants in it. NASA recommends 15 to 18 medium to large size plants for 1,800-square-foot home for optimum air quality." [...] A Facebook post claims that according to a NASA study, six to eight snake plants could produce enough oxygen to keep humans alive in a room with no airflow. We found no evidence to support that claim. A 1989 NASA study found that snake plants could remove certain toxins from small sealed spaces under certain conditions. But it did not examine whether snake plants would be able to keep humans alive in sealed rooms. Other researchers have questioned the NASA study’s findings and found that relying on plants is an impractical way of cleaning indoor air.