Emission norms India

Emission norms India

Kamaraj IAS Academy | Emission norms India
  • October 29, 2018, 4:11 pm


‘Bharat Stage’ which signifies the emission regulation standards set by Indian regulatory bodies. These emission standards were set by the central government to keep a check on the pollutant levels emitted by vehicles that use combustion engines varies from BS I to VI. To bring them into force, the Central Pollution Control Board sets timelines and standards which have to be followed by automakers.

Also, the BS norms are based on European emission norms which, for example, are referred to in a similar manner like ‘Euro 4’ and ‘Euro 6’. These norms are followed largely by all automakers across the globe and act as a good reference point as to how much does a vehicle pollute. To wrap it up and put it simply, Bharat Stage emission norms are largely similar to the European emission norms followed globally.

Technology Upgradation for BS V and BS VI

BS V: Diesel Particulate Filter (DPF): It is a cylinder mounted vertically inside the engine compartment. It traps particulate matter or soot in the filter but this has to be removed for better performance. This removal process is known as regeneration under which collected soot or PM is burnt off at high temperature say 600 0C with tiny amount of ash as residue. 

BS VI: Selective Catalytic Reduction Technology (SCR): It reduces oxides of nitrogen by injecting an aqueous solution or Diesel Exhaust Fluid (DEF) which contains ammonia and react with NOx to convert/reduce NOx into nitrogen, water and tiny amount of CO2. The SCR technology has potential of reducing emission of NOx up to 90%.

Then what is the problem?

  • While the application of a stricter emission norm may sound good, especially amidst the mounting concerns over the ever-rising pollution levels in the country, there’s a lot more to it than just that.
  • Firstly, it takes years for automakers to develop a new kind of an engine or to tweak around with the current ones used in their vehicles. Once the research and development is over, the task of setting up full scale production comes up.
  • All of this comes at a cost which eventually makes the vehicle more expensive for the end customer of the product and that can be a cause of concern for automakers given how price sensitive the Indian market is.
  • Automakers were supposed to make their models BS IV compliant by April 1, 2017. While some automakers have met the targets and updated their products, there is a huge stock of vehicles left to be sold into the market that are BS-III compliant and as per the latest SC decision, they won’t be able to do so.
  • As of now, BS IV will be implemented from April 1, 2017. Those looking to purchase a vehicle will have to spend a higher amount than before to own one.
  • But, the larger aim for the automotive sector as a whole is to implement BS VI emission regulation by the year 2020 in India. Yes, BS VI and yes, BS V will be skipped.
  • This will require a huge amount of investments to make the oil refineries capable of producing a better quality of fuel and also investments in the infrastructure to make that fuel available across the country


Table 1: Indian Emission Standards (4-Wheel Vehicles)





India 2000

Euro 1



Bharat Stage II

Euro 2


NCR*, Mumbai, Kolkata, Chennai


NCR*, 13 Cities†



Bharat Stage III

Euro 3


NCR*, 13 Cities†



Bharat Stage IV

Euro 4


NCR*, 13 Cities†



Bharat Stage V

Euro 5

(to be skipped)


Bharat Stage VI

Euro 6


Delhi NCR




* National Capital Region (Delhi)

† Mumbai, Kolkata, Chennai, Bengaluru, Hyderabad, Ahmedabad, Pune, Surat, Kanpur, Lucknow, Sholapur, Jamshedpur and Agra