Question

Long answer type question

How BS emission standards changed over time? Why is it essential?

Answer 1

i. According to the new fuel policy, the norms are set to reduce sulphur and aromatic content of petrol and diesel. Another provision is the up-gradation of engines. For this, Bharat stage emission standards (BS) are set. These standards are equivalent to Euro norms and have evolved on similar lines as Bharat Stage II (BS-II) to BS-VI from 2001 to 2017.

ii. It is essential to change BS emission standards in order to limit the release of air pollutants from the internal combustion engine.

iii. In 2001, Bharat stage II emission norms were set for CNG and LPG vehicles. As per Bharat Stage II, the emission of sulphur should be controlled at 50 ppm in diesel and 150 ppm in petrol. Aromatic hydrocarbons should be just 42% in concerned fuel.

iv. The aim was to reduce sulphur emission to 50 ppm in petrol and diesel along with aromatic hydrocarbons to 35%. Hence, the Government of India directly adapted BS-VI in the year 2018, skipping BS V. These efforts decreased the levels of CO₂ and SO₂ in Delhi.

v. BS emission standards in cities of India:

Vehicle	Norms	Cities of Implementation
4 wheelers	Bharat Stage II	All metro cities
4 wheelers	Bharat Stage III	Throughout the country since October 2010
4 wheelers	Bharat Stage IV	13 megacities (Delhi and NCR, Mumbai, Kolkata, Chennai, Bengaluru, Surat, Kanpur, Agra, Lucknow, Solapur) since April 2010.
2 wheelers	Bharat Stage III	Throughout the country since October 2010
3 wheelers	Bharat Stage III	Throughout the country since October 2010