50 houseplants that filter air

Houseplants are a great way to clean the air in your home, and there are studies to prove it. For more than 30 years, B.C. “Bill” Wolverton, a retired civilian scientist for NASA, investigated the use of plants as air- and water-purifying systems for enclosed environments in space missions. Below is the list of 50 houseplants that he found worked best. If you're interested in learning more, buy his book, How to Grow Fresh Air: 50 House Plants that Purify Your Home or Office and find out about the exact rankings, and which one is best for filtering out which chemicals!

Boston fern
Florist's mum
Gerbera daisy / Barberton daisy
Dwarf date palm
Dracaena "Janet Craig"
Bamboo palm
Kimberley queen fern
Rubber plant
English ivy
Weeping fig
Peace lily
Areca palm
Corn plant (Dracaena fragrans)
Lady palm
Schefflera
Dragon tree
Warneckei dracaena
Lily turf
Dendrobium orchid
Dumb cane (Exotica)
Tulip
Ficus alii 
King of hearts / bleeding heart
Parlor palm
Azalea 
Chinese evergreen
Spider plant
Banana 
Red emerald philodendron
Dumb cane (Camilla) 
Elephant ear philodendron 
Golden pothos
Norfolk Island pine
Wax begonia
Prayer plant
Oak leaf ivy / grape ivy
Christmas cactus
Lacy tree philodendron 
Arrowhead vine 
Heart-leaf philodendron
Lady Jane
Peacock plant
Poinsettia
Cyclamen
Moth orchid
Urn plant
Croton
Snake plant
Aloe vera
Kalanchoe

Notes and legend

• Italics denote the shade-tolerant plants (semi-shade).
• Bold italics denote the most shade tolerant plants (full shade).
• The list is ranked with the plants best at filtering out formaldehyde at the top. Rankings by ability to filter out xylene, toluene or ammonia will be different.
• Red plants are toxic to children, cats and/or dogs.
• Green plants are non-toxic.

Much of the toxicity information was from ASPCA or from this site on Wikipedia that lists air-filtering plants.