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Green Office Space

Green Office Space


The Building Physiologist

The Building Physiologist


written by Dorit d’Scarlett

Most of us are aware that having plants around makes us feel better, but you may not realise just how beneficial they actually are. Plants in offices and schools make workers and students alike more productive, take fewer sick days, make fewer mistakes and they are generally happier chappies when their environment is ambiently enhanced with interior landscaping or Green Space. So how do we actually know this and why is it so?Green Classroom

Well, in the 1980’s NASA started conducting experiments to create a sustainable, closed ecological life support system. Dr. B. C. Wolverton of the Environmental Research Laboratory of the John C. Stennis Space Center in the US found the key to achieving this was the use of that blast from the past, the humble 70’s houseplant. The Peace Lily, for example,  topped NASA’s list for removing all three of the most common VOCs — or volatile organic compounds – formaldehyde, benzene and trichloroethylene, from the air.  It can also combat toluene and xylene. VOC’s come from various sources including furnishings, carpets, cleaning products that are synthetic or treated. The way plants remove chemical contaminants from the air is by pulling them through the tiny openings in their leaves. Trace chemicals in the atmosphere are absorbed and then biodegraded by plant leaves and roots, the soil, and micro-organisms. Particular plants are better at removing certain toxins. The Boston fern, for example, can remove up to 1.8mg of formaldehyde per hour (a carcinogen found in particle board and furnishings)

Peace Lily



Other plants that are highly effective at removing formaldehyde, especially from newly renovated spaces are:


  • Bamboo palm
  • Dracaena Marginata
  • Dracaena Warneckei
  • English Ivy (Hedera helix) –(toxic to cats)
  • Rubber Plant (Ficus robusta) (toxic to cats)
  • Golden Pathos
  • Green Spider plant
  • Mother-in-law’s tongue (toxic to cats)
  • Peace lily (not a real lily therefore not toxic to cats)

 Chart showing common VOC’s, their sources and effects on humans:



Effects on Humans

BenzeneA commonly used solvent, also found in fuels.


Inks, oils, paints, plastics, rubber, gasoline, detergents, pharmaceuticals, dyes, tobacco smoke and synthetic fibers.

Skin and eye irritation (including drying, inflammation, blistering and dermatitis), dizziness, weakness, headache, nausea, blurred vision, respiratory problems, tremors, irregular heartbeat, liver and kidney damage, loss of appetite, drowsiness, nervousness, psychological disturbances, diseases of the blood system and carcinogenicity.

Formaldehyde – A disinfectant, preservative, and curing agent.


Particle board, pressed wood, foam insulation, paper bags, waxed papers, facial tissues, stiffeners and wrinkle resisters, water repellents, fire retardants, binders in floor coverings, carpet backing, permanent press clothes, natural gas, kerosene and cigarette smoke.

Irritation of mucous membranes of the eyes, nose and throat, allergic contact dermatitis, respiratory problems, eye irritation, headaches, asthma and carcinogenicity to the throat.

Trichloroethylene – A commercial product for industrial use.


Metal degreasers, dry cleaners, printing inks, lacquers, varnishes and adhesives.

Potent carcinogenicity to the liver.

Plants also absorb carbon dioxide during the day (we exhale 40,000 parts per million of CO2 with every breath) and release oxygen. When carbon dioxide levels in an office get too high through lack of fresh air (oxygen supply) we start to become drowsy, suffer from brain fog and headaches and our performance significantly declines.

Spider PlantPlants help to balance the humidity levels in a dry environment (air conditioners and heaters dry out the air)by evaporation of moisture from the soil and dishes as well as via transpiration of water from their leaves. A study conducted by Dr Virginia Lohr at Washington State University found that when plants were placed in offices, the relative humidity increased significantly and actually stabilized at the recommended range of 30 to 60 percent. Without plants the relative humidity in offices was slightly below the recommended range for human comfort levels.  The research recorded the relative humidity of office space in a building with a central, forced-air system in the presence and absence of plants. Measurements were taken during four consecutive winter months. Once each week, plants were added or removed as required. Humidity and temperature were recorded every six hours. A variety of plant species were used. Air exchange rates were estimated to average one to two air changes per hour.

Plants that increase humidity levels well and are easy to look after are:

  • Palms: Areca palm, Bamboo palm, Dwarf date palm, Lady palm,
  • Boston Fern, Dwarf banana, Gerbera daisy, Rubber plant.

Plants reduce airborne mould and bacteria, their root microbes converting these pollutants into food for the plant, and they stabilise relative humidity reducing mould growth.

Aside from all this the psychological benefits of being with nature in an otherwise sterile office environment can’t be forgotten.

NASA researchers suggest efficient air cleaning is accomplished with at least one plant per 100 square feet of home or office space. A two-year study conducted by Tove Fjeld, a professor at the Agricultural University, Oslo, found the following reductions in ailments in an office after plants were introduced:

Fatigue 20%
Headache 45%
Sore/dry throat 30%
Cough 40%
Dry facial skin 25%

Wolverstone who conducted the original space experiments suggests that we would all benefit from improving the air quality in our “personal breathing zone.” This is an area of six to eight cubic feet where you spend most of your working day. Jon Naar, author of “Design for A Livable Planet: How You Can Help Clean Up the Environment” (Harper & Row, 1990), suggests 15 to 20 plants are enough to significantly improve the air quality in a 150square meter area.

I hope this inspires you to add a few plants to your work environment because your work environment effects your health and this in turn effects your endgame!

 mould cartoon


Godish, Thad (2001). Indoor Environmental Quality. New York: CRC Press. pp. 196-197. ISBN 1-56670-402-2

Prescod, A.W. (1992). More indoor plants as air purifiers. Pappus, 11:4.

Sick Building Syndrome, National Safety Council. (2009) Retrieved 2014-05-01

 Sick Building Syndrome, National Health Service, England. Retrieved 2014-05-01.

 Sick Building Syndrome – Fact Sheet, United States Environmental Protection Agency. Retrieved 2014-05-01. 

United States Environmental Protection Agency (1991). Sick building syndrome. Air and Radiation, Indoor Air Facts, 4.

Wolverton, B.C. (1990). Interior Landscape Plants and Their Role in Improving Indoor Air Quality. Wolverton Environmental Services Inc., Picayune, Mississippi.