Review of Air Quality Objectives



The Air Pollution Control Ordinance (Cap. 311) sets out Air Quality Objectives (AQOs) that the Administration should aim to achieve as soon as reasonably practicable and to maintain thereafter to safeguard the health of the community. The current AQOs took effect in January 2014. Under the APCO, the Secretary for the Environment (SEN) is required to review the AQOs at least once every five years and submit a report of the review to the Advisory Council on the Environment (ACE).

The Environment Bureau and Environmental Protection Department embarked on the review in mid-2016 and completed the review in December 2018. A review report was submitted to ACE in February 2019. We are consolidating and analysing the views received during the consultation period. The final recommendations will be released later.


Guiding Principles

  1. the AQOs should be set with a view to protecting public health;
  2. the AQOs should be updated by benchmarking against the Air Quality Guidelines (AQG) and Interim targets (ITs) published by the World Health Organization (WHO); and
  3. a progressive approach be adopted in updating the AQOs with a view to achieving the WHO AQG as a long-term goal with reference to international practices, latest technological developments and local circumstances.


Key tasks

  1. appraising the latest development in respect of air science and the health effects of air pollution;
  2. examining the current air pollution levels and trends, and progress and effectiveness of committed air quality improvement measures;
  3. identifying new practical air quality improvement measures and conducting cost benefit analysis of the measures;
  4. developing an air quality management plan for further improving air quality; and
  5. assessing air quality in future under different control scenarios and the scope for further tightening the AQOs.


Engagement with stakeholders

Under this review, the Under Secretary for the Environment (USEN) led an AQO Review Working Group (Working Group) to engage relevant stakeholders and gathered their views via four dedicated sub-groups on key aspects of the review, namely Air Science & Health, Road Transportation, Marine Transportation, and Energy & Power Generation. Members of the Working Group include representatives from the field of air science, health, green groups, chambers of commerce, professional bodies, relevant trades and representatives from relevant Government bureaux and departments.

More information on the Working Group

More information on the Sub-groups


Other Emission Sources
The review has also engaged other relevant stakeholders to explore possible new air quality improvement measures on other emission sources not covered in the sub-groups, including products containing volatile organic compounds, non-road mobile machinery, cooking fume and civil aviation. Information can be found here.


Public Engagement
The public engagement exercise ended on 14 October 2017. Relevant materials are available here.
Public Consultation
The public consultation exercise ended on 11 October 2019. Relevant materials are available here

Related Documents:
Panel on Environmental Affairs, Legislative Council 
Overall strategy for improving air quality (CB(1)233/19-20(03), 16 December 2019)pdf    
(Note: Please refer to paragraphs 32-37 and Annex B for details of the Review of the Air Quality Objectives (AQOs) public consultation findings and final recommendations.)
Advisory Council on the Environment




User review date: 
Thursday, 28 March, 2019