Plants can add a lot to a room. They can lift the spirit, beautify a space, and even add oxygen in small amounts. A recent news release from the Professional Landcare Network (PLANET), takes that a step further and claims that the key to fresh air indoors and healthy breathing is plants, and lots of them. “All plants add oxygen and create a healthier indoor environment,” says Chris Raimondi, chairman of PLANET’s Interior Specialty Group. “In addition, some plants provide the added benefit of removing toxins from the air.”

In an age of naturopathic remedies and organic solutions for everyday living, can houseplants be the next Albuterol? Dr. Barbara J. Bond, professor of forest physiology in the Department of Forest Ecosystems and Society at Oregon State University, helps clarify the place of plants in healthy breathing.

Before discussing air cleaning abilities, it’s essential to examine the word “toxin.” It’s a frightening word whose meaning Bond explains: “A ‘toxin’ is a poisonous compound. Technically, toxins are poisons that are created by living cells.” According to the Environmental Protection Agency, the only toxin dangerous to humans that plants have proven able to remove is carbon dioxide, produced by human breath.

The EPA says that the only available study of the use of plants to control indoor air pollutants couldn’t determine any benefit in the use of plants. Furthermore, the EPA warns that plants in certain situations can make air more polluted, as the damp soil required to grow them is a breeding ground for unhealthy micro-organisms.

Bond says that it is important to recognize that there are all kinds of chemicals that are ingested every day that are perfectly safe.

“Carbon dioxide falls into this category. We breathe CO2 with every breath we take and it is completely harmless. But at very high concentrations, CO2 can become poisonous, and because CO2 is produced by living organisms, its poisonous properties make it a toxin.”

Bond maintains that plants can increase breathability; that is, the amount of oxygen, in a room. However, that’s only under particular circumstances, like when a room has poor air circulation, but a lot of plants.

She says, “Most building codes require that the air in buildings is exchanged with outside air enough so that the indoor air does not usually become depleted in oxygen.” Bond adds that it’s important to realize that plants can’t do their magic without sunlight.

“It takes a large number of plants in a sunny room to produce enough oxygen to be useful for making indoor air more breathable.”