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Air Quality and Targets

Air Pollution

Air Quality in Singapore

Like many other major cities, air emissions from the industries and motor vehicles are the two key sources of air pollution domestically. Transboundary smoke haze from the land and forest fires in the region are also problems which affect Singapore’s air quality intermittently during the South West Monsoon period from August to October.

Integrated urban and industrial planning, as well as development control, has enabled the government to put in place preventive air pollution control measures during the planning stage. In addition, legislation, strict enforcement programmes and air quality monitoring have helped to ensure that air quality remains good despite our dense urban development and large industrial base.

As such, Singapore enjoys an air quality better than many cities in Asia and is comparable with the air quality of US and European cities. We have also been faring well, with the PSI in the ‘Good’ and 'Moderate' range 97% of the time in 2014.

Singapore's air quality targets, sulphur dioxide emission inventory, industrial and vehicle emission standards are detailed below.

Air Quality Targets

As international air quality benchmarks like the World Health Organisation Air Quality Guidelines (WHO AQGs) are being constantly reviewed, NEA formed the Advisory Committee on Ambient Air quality in July 2010 to advise on a set of air quality targets for Singapore to safeguard public health. The committee was chaired by the NEA with representatives from various stakeholders in the public sector and institutions of higher education*.

The committee completed its work in July 2011 and its recommendations were based on the assessment that the WHO AQGs are internationally recognised and rigorous as they are backed by scientific findings and health studies. The committee also advised that NEA work towards achieving the WHO AQGs for all air pollutants in the long term. The executive summary of the recommendations by the Advisory Committee on Ambient Air Quality is attached. 

Executive summary

*Full list of representatives: Ministry of Health, Ministry of Trade and Industry, Economic Development Board, Energy Market Authority, Ministry of Manpower, Ministry of Community Development, Youth and Sports, Singapore Environment Council, Singapore Tourism Board, National University of Singapore, Nanyang Technological University, National Health Group and the Singapore Health Services.

MEWR, together with NEA, reviewed the recommendations of the Advisory Committee and the Sustainable Singapore Blueprint (SSB) commitments launched in 2009 to achieve an annual mean of 15µg/m3 of SO2 and 12µg/m3 of PM2.5 by 2020 and has worked with relevant government agencies and various stakeholders to arrive at a set of revised national air quality targets pegged to the WHO AQGs. The targets are in Annex I.

To work towards attaining the air quality targets by 2020, NEA has put together a roadmap with a set of abatement measures to achieve sustainable growth and development while maintaining public health and economic competitiveness. The abatement measures are summarised in Annex II.

Annex I: Singapore Ambient Air Quality Targets

Pollutant Singapore Targets by 2020 Long Term Targets
Sulphur Dioxide (SO2) 24-hour mean: 50µg/m3
(WHO Interim Target)

Annual mean: 15 µg/m3
(Sustainable Singapore Blueprint target)
24-hour mean: 20µg/m3
(WHO Final)
Particulate Matter
(PM2.5)
Annual mean: 12µg/m3
(Sustainable Singapore Blueprint target) [1]

24-hour mean: 37.5µg/m3
(WHO Interim Target)
Annual mean: 10µg/m3



24-hour mean: 25µg/m3 (WHO Final)
Particulate Matter
(PM10)
Annual mean: 20 µg/m3
24-hour mean: 50 µg/m3
(WHO Final)
Ozone 8-hour mean: 100µg/m3
(WHO Final)
Nitrogen Dioxide (NO2) Annual mean: 40µg/m3
1-hour mean: 200µg/m3
(WHO Final)
Carbon Monoxide (CO) 8-hour mean: 10mg/m3
1-hour mean: 30mg/m3
(WHO Final)

[1] Sustainable Singapore Blueprint annual target for PM2.5 of 12µg/m3 will be retained and aligned with WHO Interim Target of 37.5 µg/m3 for 24-hour mean

Annex II: Summary of Abatement Measures

Pollutant Measures
Sulphur Dioxide (SO2) With effect from July 2013, NEA mandated the supply of Near Sulphur-Free Diesel (NSFD) with a sulphur content of 0.001% to pave the way for Euro V emission standards for diesel vehicles and further reduce SO2 emissions from diesel vehicles and industries.
With effect from 1 October 2013, NEA will mandate cleaner petrol for motor vehicles with sulphur content lower than 0.005% to pave the way for the Euro IV emission standards. This will also reduce HC and NOx which will give rise to ozone.
NEA, together with EDB, will work with refineries to improve their processes and decrease their SO2 emissions. Power stations are also working towards using cleaner fuels for their energy needs in order to lower their SO2 emissions. As the power stations and industries switch to the use of cleaner fuels to reduce SO2, there will also be a simultaneous reduction in other pollutants including PM2.5.
Particulate Matter
(PM2.5 + PM10)
With effect from July 2013, NSFD with sulphur content less than 0.001% sulphur is mandatory for motor vehicles and industries.
With effect from 1 January 2014, emissions standards have been tightened to Euro V emission standards. The particulate emissions of Euro V diesel passenger cars are significantly lower than that of Euro IV diesel cars.
Early Turnover Scheme to incentivise owners of Pre-Euro and Euro I diesel commercial vehicles to retire their vehicles and upgrade to Euro V-compliant vehicles.
With effect from 1 January 2014, all in-use diesel driven vehicles are required to achieve a smoke opacity reading of 40 Hartridge Smoke Units (from 50 Hartridge Smoke Units) or below during vehicle inspection.
Ozone[2] From 1 April 2014, new petrol vehicles will have to comply with Euro IV emission standards.
Emissions standards for motorcycles and scooters will be revised to Euro III standards from 1 October 2014.

[2] Ozone is not directly emitted but is formed through complex chemical reactions involving hydrocarbons (HC) and nitric oxide & nitrogen dioxide (NOx) in the presence of sunlight. HC and NOx emitted from motor vehicles, industries, power stations and refineries are the precursors for ozone formation.

Sulphur Dioxide (SO2) Emission Inventory

Sulphur dioxide (SO2) is one of the six pollutants that we track and monitor closely in Singapore, with the others being particulate matter (PM10), fine particulate matter (PM2.5), nitrogen dioxide, carbon monoxide and ozone. Sources of SO2 emissions in Singapore include industries such as refineries and power stations, as well as motor vehicles.

The 2015 SO2 emission inventory, developed based on extensive emissions data collected from various sources, is shown in the table below. While the companies operate within permissible limits and form part of the Chemical Cluster (comprising petroleum, petrochemicals and specialty chemicals sectors which contribute to more than a third of the total manufacturing output in Singapore), it is important to continue striving for improved emission targets. The industries are also working towards lower emission levels as part of the overall goal of achieving better air quality for Singapore over the long term.

Sources Emitters SO2 Emissions (tonnes) Contribution of SO2 Emissions
Refineries Shell 27,701

93.1%

Singapore Refining Company 22,996
ExxonMobil 23,904
Power Stations
Power Seraya 66

1.7%

Tuas power 0
Senoko Power  0
TP Utilities (BMCC) 1,273
Other Industries Sembcorp Industries 0

5.1%

ExxonMobil Petrochemical 2,129
Linde Syngas 491
Mitsui Phenol 12
Petrochemical Corporation of Singapore 91
Evonik Methionine 148
Other Fuel Oil Users 1,180
Diesel Users 10
Motor Vehicles Petrol Vehicles 79

0.1%

Diesel Vehicles 31
Total 80,111

100%

Industrial Emissions

The NEA’s Source Emission Test Scheme for industries requires industries to conduct source emission tests on their own or engage accredited consultants to do so on their behalf. This allows industries to monitor their air emissions regularly and to take measures to ensure compliance with the prescribed air emission standards.

Motor Vehicles

Motor vehicles are a major source of air pollution. To control the emissions generated by motor vehicles, NEA regulates the type and quality of fuel that can be used in Singapore, and also sets minimum exhaust emission standards for all vehicles.

Smoky Vehicles

NEA takes stringent enforcement actions against smoky vehicles on the roads. Under the Environmental Protection and Management (Vehicular Emissions) Regulations, it is an offence for any vehicle to emit visible smoke while in use on the road. The rationale is to minimise pollution to the environment  and safeguard public health as the visible smoke contains fine particulate matter. Owners of smoky vehicles can be fined up to a maximum of $2,000 for the first offence and $5,000 for subsequent offences. Currently, in-use diesel vehicles are required to undergo and pass the Chassis Dynamometer Smoke Test (CDST) during the periodic vehicle inspection conducted at the authorised vehicle inspection centres.  Since 1 January 2014, to pass the CDST, the smoke opacity limit has been tightened from 50 HSU to 40 HSU. Diesel vehicles that are maintained and serviced properly will not have difficulty passing the stricter CDST limit.  Owners of vehicles that do not pass or marginally pass the CDST will be informed by the inspection centres to send their vehicles for immediate servicing/repair.

It is the responsibility of every owner of a vehicle to ensure that the vehicle is in good condition before using it on the road. Besides regular servicing and vehicular maintenance, the driver should avoid overloading the vehicle or dragging the engine while driving. For 2-stroke motorcycles, the cause of smoke emission is usually due to incorrect dosage of lubricating oil or a clogged exhaust system.

Idling Engines

Under the Environmental Protection and Management (Vehicular Emissions) Regulations, it is an offence for the driver of a motor vehicle to leave the engine of the vehicle idling when the vehicle is stationary for reasons other than traffic conditions, except when the engine is needed to operate on-board equipment such as in the case of ambulances, fire engines, freezer trucks and concrete-mixer trucks. The rationale is to minimise pollution to the environment and safeguard public health. Turning the engine off when the vehicle is stationary will also save fuel. Under the regulations, the driver is liable to be fined up to $2,000 for the first offence. For second and subsequent offences, the driver is liable to a fine not exceeding $5,000. 

As part of NEA’s outreach efforts to raise public awareness, NEA regularly engages stakeholders such as the Singapore School & Private Hire Bus Owners’ Association, the Singapore School Transport Association, the Public Transport Operators (Bus/Taxi Operators) and the National Association of Travel Agents Singapore (NATAS) to disseminate educational messages and pamphlets to their drivers. NEA has also worked with schools to distribute educational materials such as posters and pamphlets to educate and remind parents as well as private school transport operators to switch off their vehicle engines while waiting to pick up the school children. In addition, NEA works closely with the authorised vehicle inspection centres (VICOM, JIC Inspection Services and STA Inspection) to distribute educational pamphlets and car decals during the periodic  vehicle inspections in order to remind motorists that it is an offence to leave the engine of the vehicle idling while stationary.

If you spot vehicles with idling engines or smoky emissions, you are encouraged to report them to NEA via the following platforms with details of the vehicle registration number, location, date and time of the incident.

 

• NEA hotline: 1800-CALL NEA (1800-2255 632)
• Feedback: Online Feedback Form
• MyENV Mobile App: iPhone/Android

Download brochures for more details:

Brochure for smoky vehicle 

Brochure for idling engines (brochure-cover and inner-pages

For further details on the regulations governing motor vehicle operation, importation and licensing, click here.

 

Off-Road Diesel Engines

With effect from 1 July 2012, all off-road diesel engines to be imported for use in Singapore are to comply with the EU Stage II, US Tier II or Japan Tier I  off-road diesel engine emission standards. Off-road diesel engines are any equipment or machinery with diesel engines as the main or auxiliary prime mover and not registered with the Land Transport Authority (LTA) for use on public roads.  Examples include construction equipment such as cranes, excavators, forklifts and power generators. Diesel engines used in ships, railways, locomotives and aircraft do not fall under this regulation.

All newly-imported off-road diesel engines as of 1 July 2012, both new and used, intended for use in Singapore must comply with the stipulated emission standards.  This regulation includes those with engine power above 560kW. Standby generators above 560kW imported for use in Singapore are given a grace period of up to 31 Dec 2013 to comply with the stipulated emission standards.

During the grace period, all standby generators above 560kW shall comply with the US Tier I emission standards and companies are required to write in to NEA with their request. The engine or off-road diesel equipment can be sent to an overseas or Singapore accredited laboratory for an emissions test according to the ISO 8178 standards.

Net Power (kW) Singapore
(Mandatory Standard)
>560 US Tier II
130 < P <560 US Tier II or EU Stage II or Japan Tier I
75 < P <130 US Tier II or EU Stage II or Japan Tier I
37 < P <75 US Tier II or EU Stage II or Japan Tier I
19 < P <37 US Tier II or EU Stage II or Japan Tier I
< 19 US Tier II or Japan Tier I

For new off-road diesel engines, NEA accepts common emissions test reports for each make and model.

For used off-road diesel engine, NEA requires an emissions test to be conducted on each and every unit before it can be allowed for use in Singapore.

It is an offence under the Environmental Protection and Management (Off-Road Diesel Engine Emissions) Regulations for any person to use off-road diesel engines imported into Singapore on or after 1 July 2012 if they do not comply with the stipulated emission standards.

The application form for approval to import and use off-road diesel engines with effect from 1 July 2012 can be downloaded from the following website and emailed to Contact_NEA@nea.gov.sg.

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