The Indoor Air Quality (IAQ) Objectives for offices and public places will be revised from July 1, the Environmental Protection Department announced today.

The revision tightens the concentration levels of carbon monoxide, respirable suspended particulates and radon, while adding short-term objectives for formaldehyde and nitrogen dioxide, as well as a new parameter of mould.

Meanwhile, the three physical parameters of room temperature, relative humidity and air movement which are not directly related to the IAQ will be removed.

The department made reference to the latest World Health Organization guidelines and took into account the local circumstances when revising the objectives.

Implemented in 2003, the Indoor Air Quality Certification Scheme for Offices & Public Places encourages property owners and management to adopt good air quality management practices in their premises.

Premises used as offices or public places that are served by mechanical ventilation and air conditioning systems may join the scheme and must carry out certification of all IAQ parameters regularly.

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