Environment Hong Kong 2006 Chapter 1: IntroductionChapter 2: Cross-boundary and International Co-operationChapter 3: Community AwarenessChapter 4: Customer Service and PartnershipChapter 5: Environmental Assessment and Planning
Chapter 6: AirChapter 7: NoiseChapter 8: WasteChapter 9: WaterChapter 10: ConservationChapter 11: Environmental Compliance
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Chapter 6 Air

To protect the health and well being of the community by achieving and maintaining satisfactory air quality through intervention in the planning process and by enforcing the controls in the Air Pollution Control Ordinance and the Ozone Layer Protection Ordinance.
Highlights in 2005
  • Introduced a cap on emissions from power plants.

  • Reached agreement with traders to impose limits on volatile organic compounds in products.

  • Introduced Euro IV standards for petrol and motor vehicles.


Air quality in Hong Kong has become an emotive issue for many people. The high occurrence of smog has led to complaints about the problem and worries about the health impacts. It has also masked the progress we are making on improving air quality. The Environmental Protection Department (EPD) has introduced a number of programmes to control local air pollution, particularly as it affects human health. We are also working closely with the Guangdong Environmental Protection Bureau to address regional pollution (see Chapter 2 for details). Underpinning these efforts is the principle that polluters should take responsibility for controlling their emissions.

Our motor vehicle emissions control programme, for instance, requires vehicle operators to pay for cleaner fuel and, with Government support, ensure older vehicles are fitted with pollution control devices. Power companies, who are the biggest single source of smog-creating pollutants in Hong Kong, are being subject to stricter controls on emissions from their plants. Suppliers of products containing volatile organic compounds, a smog-creating substance found in such everyday items as paints and hairspray, are also facing controls. The success of these measures represents growing acceptance of polluter responsibility, a necessary and important development in our efforts to secure cleaner air for Hong Kong.

We are working closely with the Guangdong Environmental Protection Bureau to address regional air pollution.


Some 108 premises have received Indoor Air Quality Certification since September 2003 - 13 are "Excellent" and 95 "Good". A list of sites and further information are available at the two web sites below:


The EPD headquarter's reception at Revenue Tower has achieved  "Good Class" IAQ certification.


The number of days in which the Air Pollution Index (API) exceeded 100, meaning pollution was "very high", dropped in 2005 due to favourable meteorological conditions and continued efforts by both Hong Kong and Guangdong to curb regional air pollution.

Annual Record of API exceeding 100 at air quality monitoring stations

Fossil Fuel Emissions

The Government has devoted considerable resources to controlling motor vehicle pollution in recent years with measurable success (see box). Between 1999 and 2005 street-side levels of nitrogen oxides (NOx) fell 17 per cent and respirable suspended particulates (RSPs) fell 14 per cent. Unfortunately, these achievements have been clouded by incidents of smog. Here the main emitting source is less apparent to the average person on the street. Power plants are in fact Hong Kong’s biggest contributors to regional air pollution. Most people are unaware of the problem because the plants are tucked away in a remote area of the New Territories and on Lamma Island.


The EPD has achieved important success in controlling motor vehicle emissions. Between 1999 and 2005, we reduced roadside nitrogen oxides by 17 per cent and respirable suspended particulates by 14 per cent. These achievements have tended to be clouded by a decline in general air quality, but they are a significant achievement in terms of reducing people’s exposure to harmful air pollutants.

Vehicles are the main source of these pollutants and the number of smoky vehicle spottings has dropped dramatically since 1999, by 80 per cent. Our programme has involved switching taxis and public light buses from diesel to cleaner liquefied petroleum gas (LPG) or electric vehicles, and fitting older diesel vans and trucks with pollution control devices. These measures were supported by $1.4 billion in Government grants.

The EPD is continuing to tighten controls on motor vehicle emissions. In January 2005 Euro IV petrol standards were adopted at the same time as the European Union. The EPD has also made Euro IV motor diesel – ultra low sulphur diesel – the statutory standard since April 2002, enabling a quick reduction in particulate and nitrogen oxide emissions from diesel-fuelled vehicles. Hong Kong is three years ahead of the European Union in that regard. Euro IV standards for vehicles come into effect in January 2006, in step with the EU.

LPG public light bus.

Power plants contribute 92 per cent of Hong Kong’s sulphur dioxide (SO2) emissions, 49 per cent of NOx and 51 per cent of RSPs. Both CLP Power Hong Kong Ltd. (CLP) and The Hong Kong Electric Company Ltd (HEC) have installed low NOx burners to reduce emissions and HEC has also installed three flue gas desulphurisation units. However, the benefits of these devices are being eroded by increased power generation. Demand is being pushed up by the stronger economies in Hong Kong and Mainland China and the need for CLP to use more coal because of unstable natural gas supplies for its plant at Black Point.

Recognising the problem, the EPD acted in 2005 to promote greater polluter responsibility in power generation. Our major achievement was the imposition of a cap on total emissions from local power plants. Prior to August 2005 specified process licences for power plants limited only the concentration of pollutants in emissions (so much pollutant per cubic metre). But when emission quantities started rising, so did the quantity of pollutants in the air. From August, operators renewing their licences have been required to reduce total emissions by complying with a set of emissions caps. This new policy has resulted in power companies sourcing cleaner coal. The first plant to renew its licence, CLP’s Castle Peak, is starting to use ultra low sulphur coal to reduce the overall sulphur content to 0.3 per cent, as against a statutory limit of one per cent sulphur.

Moreover, the EPD is also encouraging CLP and HEC to adopt more innovative solutions to pollution control. A pilot emissions trading scheme is being worked out by the Hong Kong and Guangdong governments, and both CLP and HEC indicated their willingness to discuss and explore this option as a means to reduce emissions. The two power companies have also agreed to set up production-scale wind turbines in response to the Government’s interest in promoting renewable sources of energy (see Chapter 10 for details). The Government, for its part, has set air-conditioning temperature at 25.5 degrees Celsius in summer months and written to chambers of commerce asking them to follow suit. Reducing pollution from power plants will undoubtedly require a commitment from everyone to make cleaner, more efficient use of energy, not just the power companies.

A flue gas desulphurisation plant installed at Lamma power station. CLP's coal-fired power plant at Castle Peak.

Products That Pollute

Another lesser-known contributor to regional smog is volatile organic compounds (VOCs). These are not created by combustion, but emitted by everyday products such as paints, printing inks, hairsprays and aerosol insecticides. Hong Kong has pledged to reduce VOCs by 55 per cent by 2010, using 1997 as the base year, under its joint regional air quality management plan with Guangdong. Surprisingly swift progress was made towards that goal in 2005.

VOCs–containing products.

Consultations were held with suppliers during the year on a two-phase proposal for controlling VOC emissions. The EPD initially wanted paints, inks and selected consumer products to be tested and registered for their VOC content and labelled, with mandatory VOC controls phased in from 2009. However, the trade objected that labelling would be costly and impractical. After extensive consultation, the EPD proposed to proceed to simpler but more direct mandatory controls on products’ VOC contents. Encouragingly, we were able to secure the general support of the trade. The new arrangements will require some products to be re-formulated or "greener" alternatives to be sourced. For the environment, though, it means effective controls for some products can be in place as early as 2007.

The Hong Kong Government is one of very few administrations in the world to impose VOC limits on products after California, placing it at the vanguard of VOC controls. Our success has depended on suppliers recognising their responsibility to the environment and showing a more forthcoming attitude towards reducing pollution from their products. Governments can persuade and legislate, but polluters must act. Fortunately in 2005, with the acceptance of caps on VOC and power plant emissions, there were hopeful signs that this imperative is being recognised.


  • Continue to tighten caps on emissions from power plants.

  • Require power companies to install effective emission reduction devices as a primary consideration in the review of the electricity market after 2008.

  • Promote energy saving, with the Government taking the lead by cutting electricity consumption in offices by 1.5 per cent.

  • Switch to ultra low sulphur diesel in all government works projects.

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