Loading

Air Quality Objectives

Hong Kong’s Air Quality Objectives

The Air Pollution Control Ordinance (Cap. 311) sets out Air Quality Objectives (AQOs) and provides for the periodic reviewofthe AQOsat least once every five years with a view to promoting the conservation and best use of air in the public interest.

Hong Kong Air Quality Objectives

Pollutant Averaging time Concentration limit [i]  (μg/m3) Number of exceedances allowed

Sulphur dioxide

10-minute

500

3

24-hour

125

3

Respirable suspended particulates (PM10) [ii]

24-hour

100

9

Annual

50

Not applicable

Fine suspended

particulates (PM2.5) [iii]

24-hour

75

9

Annual

35

Not applicable

Nitrogen dioxide

1-hour

200

18

Annual

40

Not applicable

Ozone

8-hour

160

9

Carbon monoxide

1-hour

30,000

0

8-hour

10,000

0

Lead

Annual

0.5

Not applicable

Note:

[i]           All measurements of the concentration of gaseous air pollutants, i.e., sulphur dioxide, nitrogen dioxide, ozone and carbon monoxide, are to be adjusted to a reference temperature of 293Kelvin and a reference pressure of 101.325 kilopascal.

[ii]          Respirable suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 10 μm or less.

[iii]          Fine suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 2.5 μm or less.

Air Quality Management in Hong Kong

The overall policy objective for air quality management in Hong Kong is to achieve as soon as reasonably practicable and to maintain thereafter an acceptable level of air quality to safeguard the health and well being of the community, and to promote the conservation and best use of air in the public interest.  In this regard, we put in force an updated Hong Kong’s AQOs on 1 January 2014 to further protect public health.

The new AQOs, which are benchmarked against a combination of interim and ultimate targets under the World Health Organization's Air Quality Guidelines, are broadly comparable to the air quality standards adopted by the European Union and the United States.  We will also review the AQOs at least once every five years with a view to tightening the standards where practicable.

To attain the new AQOs, the Government has put forward a wide range of new air quality improvement measures.  In addition, the Hong Kong Special Administrative Region (HKSAR) and Guangdong Provincial Governments endorsed in November 2012 a new set of regional emission reduction targets/ranges for 2015 and 2020 respectively.  Meeting the emission reduction targets would enable the ambient air quality of Hong Kong to meet broadly the new AQOs by 2020.

Download the Table of AQO

Historical AQOs

Air Quality Compliance Status

Air Pollution Control Strategy

;

Related Documents

WHO Air Quality Guidelines for Particulate Matter, Ozone, Nitrogen Dioxide and Sulphur Dioxide, Global Update 2005


Links

Air Quality of Hong Kong

AirQuality HealthIndex

Air Quality Reports

Air Quality Objectives of Other Countries

Australia

EU

Japan

Korea

Thailand

USA

UK

Back to top
User defined date2: 
Tuesday, 31 December, 2013