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PSI


PSI (With effect from 1 April 2014)

With effect from 1 April 2014, Singapore will move to an integrated air quality reporting index, where PM2.5 will be incorporated into the current Pollutant Standards Index (PSI) as its sixth pollutant parameter. The PSI will therefore reflect a total of six pollutants – sulphur dioxide (SO2), particulate matter (PM10) and fine particulate matter (PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3).

The 3-hr PSI will take into account PM2.5 concentrations. In addition, NEA will also publish the 1-hr PM2.5 concentrations every hour.

For past 24 hour PSI reading click here. For historical PSI reading click here.


Note: Air quality based on PSI is as follows:

PSI Value Air Quality Descriptor
0 - 50 Good
51 - 100 Moderate
101 - 200 Unhealthy
201 - 300 Very unhealthy
Above 300 Hazardous
Forecast

Health Advisory for General Public

The health impact of haze is dependent on one’s health status (e.g. whether one has pre-existing chronic heart or lung disease), the PSI (Pollutant Standards Index) level, and the duration and intensity of outdoor activity. Reducing outdoor activities and physical exertion can help limit the ill effects from haze exposure. Persons who are not feeling well, especially the elderly and children, and those with chronic heart or lung conditions, should seek medical attention.

24-hr PSI

Healthy persons

Elderly, pregnant women, children

Persons with chronic lung disease, heart disease

≤100
(Good/Moderate)

Normal activities

Normal activities

Normal activities

101- 200
(Unhealthy)

Reduce^ prolonged** or strenuous*** outdoor physical exertion

Minimise^^ prolonged** or strenuous*** outdoor physical exertion

Avoid^^^ prolonged** or strenuous*** outdoor physical exertion

201 – 300
(Very Unhealthy)

 

Avoid^^^ prolonged** or strenuous*** outdoor physical exertion

Minimise^^ outdoor activity

Avoid^^^ outdoor activity

>300
(Hazardous)

 

Minimise^^ outdoor activity

Avoid^^^ outdoor activity

 

Avoid^^^ outdoor activity

** Prolonged = continuous exposure for several hours

*** Strenuous = involving a lot of energy or effort

^ Reduce = do less

^^ Minimise = do as little as possible

^^^ Avoid = do not do

Downloads

Handy Guide  

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