This section gives an overview on air pollution control in Hong Kong. For more information on Hong Kong's air quality, please visit Air Pollution Control Strategies, Air Quality Objectives, AQHI & Air Quality, Indoor Air Quality, Ozone Layer Protection, Asbestos Control, Problems & Solutions, Public Consultation, Data & Statistics, Study Reports and Guidelines & References.



Hong Kong has been facing two air pollution issues, namely local street-level pollution and regional smog problem. Diesel vehicles are the main source of street-level pollution. Smog, however, is caused by a combination of pollutants from motor vehicles, marine vessels, industry and power plants both in Hong Kong and in the Pearl River Delta region. Because of these air pollution problems, Hong Kong has yet to fully achieve the current Air Quality Objectives [see Air Quality Objectives Compliance Status]

The Hong Kong Special Administrative Region Government gives high priority to controlling both local air pollution and regional smog problems. The main strategies include:

  • Implementing a wide range of measures to control emissions from motor vehicles, marine vessels, power plants, and industrial and commercial processes locally.
  • Working with Guangdong Provincial Authorities to implement a joint plan to tackle the regional smog problem.

The structure within Government for air policy development and provision of services in air quality management is shown in the table.

Reducing Emissions from Vehicles

The levels of respirable suspended particulates (RSP) and nitrogen dioxide (NO2) at the roadside in Hong Kong have been exceeding the Air Quality Objectives over the years. Motor vehicles, especially diesel vehicles, are the main sources of these pollutants at street level in Hong Kong.


To tackle this problem, the Government has implemented a host of measures to cut vehicular emissions after 1999, such as the incentive programme to replace diesel taxis/light buses with liquefied petroleum gas vehicles, the adoption of tighter fuel and vehicle emission standards whenever practicable, the incentive programme to retrofit old diesel vehicles with particulate reduction devices, providing grants to help vehicle owners to replace their old vehicles with ones which comply with the prevailing emission standard for newly registered vehicles, stepping up the control on smoky vehicles, reduction of first registration tax for environment-friendly vehicles, etc.

The measures had brought some improvements. Compared with 1999, the roadside concentrations of some of the major air pollutants have dropped in 2015: respirable suspended particulates (RSP), sulphur dioxide (SO2) and nitrogen oxides (NOx), have been down by 51%, 70% and 50% respectively, and the number of smoky vehicles spotted has also been reduced by nearly 90%. However, nitrogen dioxide (NO2) at roadside in 2015 remained comparable to 1999.

To further improve the air quality at the roadside and tackle the roadside NO2 problem, we have embarked on additional control measures to reduce vehicle emissions.  We have adopted an incentive-cum-regulatory approach to phase out some 82,000 pre-Euro IV diesel commercial vehicles (DCVs) progressively by end 2019 involving an ex-gratia payment of about $11.4 billion and limited the service life of DCVs newly registered on or after 1 February 2014 to 15 years.  We have been funding the franchised bus companies the full cost of retrofitting Euro II and III franchised buses with selective catalytic reduction (SCR) devices, which could upgrade their emissions performance comparable to that of Euro IV or above level.  We are also fully subsidizing the franchised bus companies to procure six double-deck hybrid buses and 36 single-deck electric buses for trial.  We have also set up a $300 million Pilot Green Transport Fund to support the testing of green and innovative transport technologies applicable to the public transport sector and goods vehicle.  In addition, the Government has starting September 2014 strengthened the control of emission from petrol and LPG vehicles including the use of roadside remote sensing equipment and chassis dynamometer testing.


Image Taxis operating on liquefied petroleum gas (LPG) were introduced as cleaner alternative to replace diesel taxis


Measures and Effectiveness In Reducing Number of Smoky Vehicles Spotted

The number of smoky vehicles spotted has reduced substantially as a result of measures taken to reduce vehicular emissions in recent years

For details, please see Cleaning the Air at Street Level.

Reducing Emissions from Vessels

To control emissions from local vessels, Hong Kong has capped the sulphur content of locally supplied marine light diesel at 0.05% since April 2014. The Government has led by example by powering its fleet with Euro V diesel.  With effect from July 2015, ocean going vessels are required to switch to fuel with sulphur content not exceeding 0.5% while berthing. We also collaborate with the governments in Pearl River Delta to explore measures to reduce vessel emissions in the region.

Reducing Emissions from Industrial Sources and Power Plants

The Air Pollution Control Ordinance and its subsidiary regulations provide for the control of emissions from power plants, industrial and commercial sources, construction activities, open burning, asbestos, petrol filling stations and dry-cleaning machines.

A regulation introduced in 1990 limiting the sulphur content of industrial fuel has reduced sulphur dioxide pollution to very low levels. We have further amended the regulation in 2008 to mandate the use of ultra low sulphur diesel (with sulphur content not more than 0.005% by weight) in industrial and commercial processes.

Chart of Sulphur dioxide hit by Fuel Restriction Regulations

Power generation is one of the main air pollutant emission sources in Hong Kong. To reduce the emissions from the power sector, we have been prohibiting the installation of new coal-fired power plant since 1997, encouraging the use of natural gas for electricity generation, imposing stringent emission caps on power plants since 2005, and linking the two local power companies’ rate of return to their compliance with the emission caps requirements. In 2008, we have also stipulated the stringent emission caps for 2010 and beyond through a Technical Memorandum (TM). In 2010, we reviewed the First TM and tightened the emission caps for the power sector from 2015 onward, the compliance with which will require the power sector to maximize the use of existing gas-fired generation units and prioritize coal-fired generation units retrofitted with emission abatement facilities. Four Technical Memoranda have been issued so far. The Fourth Technical Memorandum would tighten emission caps from 2019 onwards.

As a result of the stringent control measures implemented over the past years, emissions from power plants have been substantially reduced over the years even though demand for power has increased. For more details, please visit Air Pollution Control Strategies.

Chart of Pollutant Emission from Power Plants and Electricity Consumption

Reducing Volatile Organic Compound (VOC) Emissions

VOCs are found in a lot of products such as solvent-based paints, printing inks, many consumer products, organic solvents and petroleum products. Other than motor vehicles, the use of these products releases VOCs which cause air pollution and smog (VOCs and Smog). To reduce VOC emissions, the Government has implemented control measures to recover petrol vapour released during petrol unloading and refueling at petrol stations, and to tighten emissions standards of motor vehicles in line with the European Union standards.The VOC Regulation, effective from 1 April 2007 under the Air Pollution Control Ordinance, controls the VOC content in architectural paints/coatings, printing inks and six broad categories of consumer products (i.e. air fresheners, hairsprays, multi-purpose lubricants, floor wax strippers, insecticides and insect repellents); and requires emission reduction devices to be installed on certain printing machines. The regulation was amended in 2009 to extend the control to other products with high VOC content, including adhesives, sealants, vehicle refinishing paints/coatings, and marine vessel and pleasure craft paints/coatings, starting from 1 January 2010 in phases. In 2017, the regulation was further amended to cover fountain solutions and printing machine cleaning agents with effect from 1 January 2018. 

Hong Kong NMVOC Emissions

Tackling Regional Air Pollution

Vehicles, industry and power plants in Hong Kong and the Pearl River Delta (PRD) region all contribute to a regional air pollution problem, commonly seen as smog. The Hong Kong and Guangdong governments are working on a joint plan to reduce the total amount of emissions and stop air quality from further deteriorating as soon as practicable, and in the long term to achieve good air quality for the whole region. Thanks to the joint efforts of the two governments in cutting emissions in the region, such as retrofitting power plants with flue gas desulphurization devices, phasing out highly polluting industrial plants in the PRD, introducing cleaner motor vehicle fuels and motor vehicles, etc., the air quality in the region has improved in recent years. According to the air quality monitoring results from the PRD Regional Air Quality Monitoring Network, the average annual concentrations of SO2, NO2 and RSP in the PRD Region decreased by 66%, 20% and 24% respectively as compared to the figures of 2006 when the Network started to operate.

For more details, please visit Air Pollution Control Strategies.


Ozone Layer Protection

The Ozone Layer Protection Ordinance enables Hong Kong to fully comply with international obligations under the Montreal Protocol to phase out ozone depleting substances, and to control the import and export of these substances. For details, please visit Ozone Layer Protection.

Consumptions of Ozone Depleting Substances in Hong Kong


The EPD monitors RSPs, NOx and other pollutants. It provides updates on Air Quality Health Index every hour, and prepares annual reports on air pollution levels. For details, please visit AQHI & Air Quality.


Indoor air quality (IAQ) is a growing concern. The EPD has set up an Indoor Air Quality Information Centre to provide information on IAQ and its management as well as to display products and technologies that can help improve IAQ. For details, please visit Indoor Air Quality.


Image of Help Clear the AirCitizens can help reduce air pollution by choosing public instead of personalised transport and doing such things as turning off electric lights and appliances when not in use. For more tips on reducing air pollution, please refer to Help Clean the Air.

Industry, developers and others can also play their parts by observing air pollution control laws and exercising good practices in their operations. Please refer to Guidelines & References for a full account of compliance guides and good practices.


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User review date: 
Wednesday, 26 March, 2014