IAQ Objectives for Offices and Public Places in Hong Kong

To improve IAQ and promote public awareness of the importance of IAQ, the HKSAR Government has launched a voluntary IAQ Certification Scheme for Offices and Public Places in September 2003. It features a set of twelve 2-level parameters indoor air quality objectives (Excellent Class and Good Class) as a benchmark to assess indoor air quality of premises/buildings. The table below summarises the 12 key parameters of the IAQ:

IAQ Objectives for Offices and Public Places in Hong Kong
Parameter Unit 8 Hours Average
Excellent Class Good Class
Room Temperature oC 20 to <25.5 <25.5
Relative Humidity % 40 to <70 <70
Air Movement m/s <0.2 <0.3
Carbon Dioxide (CO2) ppmv <800 <1,000
Carbon Monoxide (CO) µg/m3 <2,000 <10,000
ppmv <1.7 <8.7
Respirable Suspended Particulate (PM10) µg/m3 <20 <180
Nitrogen Dioxide (NO2) µg/m3 <40 <150
ppbv <21 <80
Ozone (O3) µg/m3 <50 <120
ppbv <25 <61
Formaldehye (HCHO) µg/m3 <30 <100
ppbv <24 <81
Total Volatile Organic Compounds (TVOC) µg/m3 <200 <600
ppbv <87 <261
Radon (Rn) Bq/m3 <150 <200
Airborne Bacteria cfu/m3 <500 <1,000

To participate in the scheme, the owner or the management of premises/building need to engage a competent examiner, who will provide suggestions to the premises/building if any IAQ problems found. After that, the examiner will conduct IAQ measurement and certify the premises/building in compliance with IAQ objectives. For more details on the IAQ Certification Scheme, please refer to the IAQ Information Centre.