Applied Ozone

Sick Building Syndrome: Causes, Symptoms and How to Fix Indoor Air

Do you get headaches or itchy eyes at work that disappear soon after you leave the building? You may be working in a “sick building”. Here is what the term means and what actually fixes the problem.

Sick building syndrome vs. building related illness

  • Sick building syndrome (SBS): occupants feel unwell or uncomfortable in connection with time spent in a building, but no specific illness or cause can be identified. Symptoms include headache, eye, nose and throat irritation, dry cough, dry or itchy skin, dizziness, nausea, difficulty concentrating, fatigue and sensitivity to odors. Most people feel better soon after leaving.
  • Building related illness (BRI): a diagnosable illness caused by airborne contaminants in the building, such as Legionnaires’ disease. Symptoms such as cough, chest tightness, fever, chills and muscle aches can take longer to clear.

The usual causes

  • Too little fresh air. After the 1973 oil embargo, many buildings cut outdoor air to about 5 cubic feet per minute (cfm) per person to save energy. ASHRAE later restored a minimum of 15 cfm per person, and 20 cfm per person in offices.
  • Indoor chemicals: volatile organic compounds (VOCs), including formaldehyde, from adhesives, carpets, upholstery, pressed wood, copiers, pesticides and cleaning products, plus combustion products from unvented heaters and gas appliances.
  • Outdoor pollution pulled inside through badly placed air intakes: vehicle exhaust, garage fumes, plumbing vents.
  • Biological contaminants: bacteria, mold and viruses growing in standing water in ducts, humidifiers and drain pans, or in water-damaged materials.

What fixes it

  1. Remove or control the source: repair leaks and water damage, maintain the HVAC system and change filters, vent copy rooms and print shops to the outside, use strong chemicals only in ventilated or unoccupied spaces, and let new furniture and carpets air out before people move in.
  2. Increase ventilation to design rates and make sure air actually reaches every occupied area.
  3. Use local exhaust in restrooms, kitchens and copy rooms.
  4. Clean the air as a supplement: good particle filters help, but filters alone do not remove gases.
  5. Talk to the people in the building: complaint logs and good communication help find the source quickly.

    6. What about ozone air purifiers?

    Ozone is an excellent tool for water, laundry and food treatment, but the EPA advises against running ozone generators in occupied rooms. At concentrations that are safe to breathe, ozone does little to remove indoor chemicals, odors or microbes, and it can react with other indoor chemicals to form irritating by-products. OSHA limits workplace exposure to 0.10 ppm averaged over 8 hours, and the FDA limits ozone output from indoor medical devices to 0.05 ppm. If you use ozone to treat a room, for example after smoke or water damage, do it while the room is empty and ventilate it before anyone returns.

    Sources