Overview

Types of Pollutants

This covers the types of air pollutants subject to environmental standards set by the Ministry of the Environment (PM2.5, ozone, nitrogen dioxide, etc.) and organic fluorine compounds (PFAS) that cause water pollution. These pollutants affect human health and ecosystems, and are subject to environmental standards and regulations.

Ministry of the Environment air pollution water pollution PM2.5 ozone PFAS environmental standards
code slug name description category standardValue
PM25 pm2-5 Particulate Matter 2.5 (PM2.5) Particulate matter with a diameter of 2.5 micrometers or less. Air Quality Standard Substances Annual average: 15μg/m³ or less, Daily average: 35μg/m³ or less
OX photochemical-oxidants Photochemical Oxidants (Ozone) Pollutants generated by photochemical reactions, primarily ozone. Air Quality Standard Substances 1-hour value: 0.06ppm or less
NO2 nitrogen-dioxide Nitrogen Dioxide (NO₂) A reddish-brown irritating gas produced by high-temperature combustion. Air Quality Standard Substances Daily average of 1-hour values: 0.04-0.06ppm or less
SO2 sulfur-dioxide Sulfur Dioxide (SO₂) A colorless irritating gas produced by combustion of fossil fuels. Air Quality Standard Substances Daily average of 1-hour values: 0.04ppm or less, and 1-hour value: 0.1ppm or less
CO carbon-monoxide Carbon Monoxide (CO) A colorless, odorless toxic gas produced by incomplete combustion. Air Quality Standard Substances Daily average of 1-hour values: 10ppm or less, and 8-hour average: 20ppm or less
SPM suspended-particulate-matter Suspended Particulate Matter (SPM) Particulate matter with a diameter of 10 micrometers or less. Air Quality Standard Substances Daily average of 1-hour values: 0.10mg/m³ or less, and 1-hour value: 0.20mg/m³ or less
PFAS pfas Per- and Polyfluoroalkyl Substances (PFAS) Forever chemicals with persistence and bioaccumulation properties. Water Pollutants Water quality standard: Combined PFOS + PFOA 50ng/L or less (effective April 1, 2026)
PFOS pfos PFOS (Perfluorooctanesulfonic Acid) A type of PFAS, with manufacturing and import banned in 2010. Water Pollutants Chemical Substances Control Law: Class I Specified Chemical Substance (manufacturing/import principally prohibited)
PFOA pfoa PFOA (Perfluorooctanoic Acid) A type of PFAS, with manufacturing and import banned in 2021. Water Pollutants Chemical Substances Control Law: Class I Specified Chemical Substance (manufacturing/import principally prohibited)
PFHxS pfhxs PFHxS (Perfluorohexanesulfonic Acid) A type of PFAS, with manufacturing and import banned in 2024. Water Pollutants Chemical Substances Control Law: Class I Specified Chemical Substance (manufacturing/import principally prohibited)

Classification of major air and water pollutants including organic fluorine compounds.