Explanation
Bharat Stage (BS) emission standards based on European regulations were first introduced in India in the year 2000.
The BS-II norms were implemented in 2000, followed by the introduction of BS-III in 2005, BS-IV in 2010, BS-V in 2019, and BS-VI in 2020. These emission standards regulate the permissible levels of air pollutants emitted by internal combustion engines in vehicles in order to reduce pollution and improve air quality.