NASA Clean Air Study


The NASA Clean Air Study was a project led by the National Aeronautics and Space Administration in association with the Associated Landscape Contractors of America to research ways to clean the air in space stations. Its results suggested that, in addition to absorbing carbon dioxide and releasing oxygen through photosynthesis, certain common indoor plants may also provide a natural way of removing volatile organic pollutants.
The study further suggested that efficient air cleaning is accomplished with at least one plant per of space, but was conducted under sealed space station conditions and research conducted since has shown mixed results in the home or office.

List of air-filtering plants

The following plants were tested during the initial 1989 study:
Plant, removes:benzeneTotal µg/h of benzene removedformaldehydeTotal µg/h of formaldehyde removedtrichloroethyleneTotal µg/h of trichloroethylene removedxylene and tolueneammonia
Dwarf date palm 1,385
Areca palm
Boston fern 1,863
Kimberley queen fern 1,328
English ivy 579402 -1,120298
Spider plant 560
Devil's ivy, Pothos plant
Peace lily 1,7256741,128
Flamingo lily
Chinese evergreen 604183
Bamboo palm 1,4203,196688
Parlour Palm 660
Lady Palm 876
Variegated snake plant, mother-in-law's tongue 1,1961,304405
Heartleaf philodendron 353
Selloum philodendron
361
Elephant ear philodendron 416
Red-edged dracaena 1,2648531,137
Cornstalk dracaena 938421
Weeping fig 940
Barberton daisy 4,4861,622
Florist's chrysanthemum 3,2051,450
Rubber plant
Dendrobium orchids 756
Dumb canes 754
King of hearts 668
Moth orchids 240
Aloe vera
Janet Craig 1,0821,361 - 2,037764
Warneckei 1,630760573
Banana 488

Additional research

Since the release of the initial 1989 study, titled A study of interior landscape plants for indoor air pollution abatement: An Interim Report, further research has been done including a 1993 paper and 1996 book by B. C. Wolverton, the primary researcher on the original NASA study, that listed additional plants and focused on the removal of specific chemicals. A different study in 2004 has also shown that the micro-organisms in the soil of a potted plant remove benzene from the air, and that some plant species themselves also contribute to removing benzene.