Indoor environmental quality (IEQ) can significantly affect the health, comfort, productivity and job satisfaction of workers in indoor environments. The following are common symptoms of poor IEQ:

• Dryness and irritation of the eyes, nose, throat, and skin
• Headache
• Fatigue
• Shortness of breath
• Hypersensitivity and allergies
• Sinus congestion
• Coughing and sneezing
• Dizziness
• Nausea

Control of air contaminants, produced either inside the building or infiltrating from outside, plays a big part in maintaining optimal IEQ. These include:

• Carbon dioxide – from human respiration and combustion sources
• Carbon monoxide – produced by combustion sources such as furnaces and vehicular traffic outside
• Chemicals off-gassed from new furniture, carpets, wall board and paint – such as formaldehyde and other volatile organic compounds (VOCs)
• Dust and fibres – from carpets, insulation materials, wall board, human skin scales, and outside sources
• Mould – water damaged locations and house plants.

In addition, the following can be assessed:

• Temperature
• Humidity
• Noise
• Lighting