The indoor air quality (IAQ) of workplaces and homes has caught the attention of scientists, entrepreneurs and the public in recent years. Studies have found pollutant levels to be greater indoors than outdoors. Good IAQ is very important for health because people spend more than 70 per cent of their time indoors. Poor IAQ can lead to discomfort and illness. Children, the elderly and people with respiratory or heart problems are particularly susceptible.

In 2003, the Environmental Protection Department issued Guidance Notes for the Management of Indoor Air Quality in Offices and Public Places, launched a voluntary IAQ certification scheme for locations with mechanical ventilation and air conditioning systems, and established IAQ Objectives for office buildings and public places. However, in 2011, the Audit Commission noted that the guidance notes included office buildings and some public places, but not schools.

Research on the IAQ of kindergartens and primary schools in Hong Kong is limited. Studies around the world have revealed that IAQ has a more significant effect on children than adults because children breathe in more air. In addition, identifying poor IAQ as the source of the problem is more difficult, as its effect on children may not show until they are older.

Poor IAQ can affect the health and school attendance of children. Maintenance issues in schools, such as those involving mould, moisture and excessive use of cleaning chemicals, have been shown to trigger asthma and allergies.