On Friday, we finished the survey that NASA did of house plants that clean the air. But that’s not the end of the story. Other scientists have since expanded on that study and added other chemicals that they wanted to study, bringing to the final number 6 chemicals that house plants remove from the air.

This later group was studied BC and JD Wolverton. BC Wolverton was one of the principal investigators in the 1989 NASA study. You can find a great chart showing a list of all the plants studied, the chemicals they remediate, and whether they are toxic to pets, summarized here.

Why would you have xylene or toluene in your home or work space? These chemicals are primarily found in copiers, printers and beauty products–so most of us come in common with them in daily life.

And while I do not have a microgram comparison for these plants, some of the best plants for removing these chemicals (which appear to have been studied together) are as follows:

Spider plant, peace lily, Chinese evergreen, bamboo palm, dracena marginata, snake plant, florist mum–in other words, most of our old friends from our other studies. Interestingly enough, dendrobium and moth (phalaenopsis) orchids also seem to work well for this purpose.

So once again, there is a plant for just about everyone in this list if you are concerned about removing these very common chemicals from your home, work space–or home office!

So far we’ve looked at plants that clean the air of TCE and benzene. Today we’ll look at formaldehyde. Unlike the other two chemicals, formaldehyde is still readily present in most of our homes and work spaces despite our best efforts. It can be found in all sorts of things from insulation and particle board furniture to grocery bags, waxed paper, tissues and paper towels. It’s used as fire retardants in our clothing and our furniture and as wrinkle resistant treatments as well. It’s even used in the glues backing our rugs! It too is found in natural gas if you heat or cook with it. It’s used in make-up products and nail polish–it’s pretty much everywhere around us!

Luckily, lots of plants remediate formaldehyde (which I wish I had known back when I had to take labs in high school and college since it gives me a splitting headache!) But now that I do know, I know how to cope if the carpet is being changed out, for example–and it really works!

NASA found these plants to be the top 5 best for removing formaldehyde from the air:

Bamboo Palm was the winner this time–it removed a whopping 76,000 plus micrograms (mcg) from the air over a 24 hour period. No other plant even came close to that number.

Janet Craig dracena was the next best plant–it removed over 48,000 mcg from the air.

The snake plant (sansevieria) came in third in this group. It removed over 31,000 mcg from the air. This is a good choice because it can live in a variety of light settings.

Dracena marginata came in next, removing over 20,000 mcg from the air.

And the Peace Lily removed over 16,000 from the air.

All of these plants are readily available just about anywhere and will grow just about anywhere. Of them all, I think the palm is probably the most finicky, simply because it needs more humidity than the rest to look good. But otherwise these plants are intermediate to low light plants that would do well in most home or office settings–but not in full sun!

On Friday, I talked about TCE, where it comes from, and what plants are best at getting it out of the air. Today I am going to discuss benzene, another chemical that’s commonly found in and around homes and work spaces.

Benzene is going to be very familiar to most of us from the smell of gasoline. It’s also found in our homes if we heat or cook with natural gas.  So most of us have some exposure to it just by driving a car or perhaps by the way we heat our homes.

Fortunately, once again, we can rely on plants (according to NASA) to remove benzene from our environment. Additionally, the NASA study hypothesizes, but was unable to definitively determine, that the beneficial bacteria in the potting mix, activated by the plants roots, also helped to remove some of the benzene. Really interesting stuff!

A list of the bacteria found in the potting mix reads like some of the probiotics compounds that some of us take for our “microbiome.”  Hmm. No wonder they say playing in the dirt is good for you!

But I digress. Here are the best plants for removing the benzene from the air:

Gerber Daisy (once again the winner) at over 107,000 micrograms (mcg) per plant in the 24 hour period! Astonishing!

Next was the Florist or pot mum at over 76,000 mcg.

Peace Lily came in third at over 41,000 mcg (let’s hear it for the flowering plants–and even one that likes low light!)

Dracena Warneckei was next at over 39,000.

And the Bamboo Palm rounds out the top 5 with just over 34,000 mcg.

What’s great about this list is that there’s a plant on here for every light situation from full sun to a dark corner and intermediate light as well. And again, these are easily obtainable–and easy to grow–plants.

First, we want to know what “TCE” is and why we want it out of our air. TCE is short hand for trichloroethylene and it is probably in most of our homes and perhaps our work spaces as well. While it is no longer commercially acceptable due to its possible carcinogenic qualities, it was once found in paints, adhesives, dry cleaning fluids, lacquer, varnish and printing ink. Depending on the age of your home or work space, it is entirely possible that TCE is persistent in some of the surfaces there or perhaps even in the soil surrounding the building.

And while we still don’t have inexpensive ways to determine whether the soil we are gardening in is contaminated, there are ways to use plants to pull contaminants out of the air. (A suggestion: If you have any suspicion that there may be toxins in your soil, build raised beds and garden in those–at least with respect to your edible crops!)

NASA found that the top plants for cleaning  the air of TCE (in a 24 hour period) were as follows:

Gerber Daisy (this one surprised me) but this plant cleaned the air better than all the other plants combined. It removed an astonishing 38,000 plus micrograms (mcg)in the 24 hour period!

Dracena marginata and Peace Lily (spathiphyllum) were next best, each removing over 27,000 mcg per plant!

Janet Craig dracena removed over 18,000 mcg per plant.

And finally, the bamboo palm removed over 16,000 mcg per plant.

All of these plants are readily available to this day in garden centers, box stores and even some supermarkets.

So if you’re concerned about an upcoming renovation where paint strippers–or even paint that’s not low VOC might be used–these are the plants to bring in and put around to take the TCE out of the air.

On Monday, we talked about some easy to care for plants to clean the air. But what if boring green–or green and white–just isn’t your thing? What if you need some flowering plants in your life? Never fear! There are some flowering plants that will clean the air as well.

Admittedly the list is shorter than the list of green plants–and for good reason, of course. Presumably it is the leaves that do most of the work of cleaning the air.

But nevertheless, there still are some flowering plants that are great air cleaners. And the list includes some plants you might not expect.

Phalaenopsis (moth) orchid (as well as dendrobium orchid)–both excellent at removing xylene and toluene. The dendrobium will cause oral inflammation if chewed however in both animals and children so it might be wise to stick with moth orchids in homes with pets or children.

Florist chrysanthemum–while this plant is a master air scrubber, removing formaldehyde, xylene, toluene and other toxins from the air, it can be poisonous to dogs and cats so it wouldn’t be wise to bring it into a home with pets.

Anthurium–these plants are great at formaldehyde, xylene and toluene so they, like the mums, are master air scrubbers. They do need a high level of light to re-flower, however. And yes, these plants are usually red. As you can see, they do come in white as well, and there is a pink form too. So there are lots of choices for your décor.