Pollutant Standards Index

Southeast Asian haze series
Haze in Borneo, 2019
History
1990s 1997 Southeast Asian haze 1997 Indonesian forest fires
2000s 2005 Malaysian haze 2006 Southeast Asian haze 2009 Southeast Asian haze
2010s 2010 Southeast Asian haze 2013 Southeast Asian haze 2015 Southeast Asian haze 2016 Malaysian haze 2016 Southeast Asian haze 2017 Southeast Asian haze 2019 Southeast Asian haze
Key topics
Chemical equator Deforestation in Borneo in Indonesia Mega Rice Project Peat swamp forest Borneo
Responses
ASEAN Agreement on Transboundary Haze Pollution Operation Haze Transboundary Haze Pollution Act 2014 People's Movement to Stop Haze
See also
Air pollution in Malaysia API Singapore PSI Social and environmental impact of palm oil
Category
v t e

The Pollutant Standards Index (PSI) is a type of air quality index used in Singapore, which is a number used to indicate the level of pollutants in air. Initially PSI was based on five air pollutants, but since 1 April 2014 it has also included fine particulate matter (PM_2.5).

In addition to the PSI derived by averaging data collected for the past 24 hours, Singapore also publishes 1-hr PM_2.5 concentrations are also published every hour.^[1]

Besides Singapore, some other countries also use air quality indices. However, the calculations used to derive their air quality indices may differ.^[2] Different countries also use different names for their indices such as Air Quality Health Index, Air Pollution Index and Pollutant Standards Index.