Bharat Emission Standards

Govt. to implement BS-VI emission norms by April 2020 –

Soon after the success of the odd-even rule in Delhi, the Supreme Court ordered the implementation of the Bharat Stage (BS)-VI emission norms earlier than the April 2021 deadline fixed by the Union government. Thus, in order to reduce pollution and promote overall public health, the government is all set to enforce stage VI emission standards by April 1, 2020.

Bharat Emission Standards – a background

The Union government launched the Bharat Stage emission norms in order to regulate the output of air pollutants from internal combustion engine equipments, including motor vehicles. The norms aim to reduce sulphur content in fuels and make changes in the engine design of automobiles to cut down on emission quantities.

The Central Pollution Control Board, which falls under the Ministry of Environment & Forests and Climate Change, formulates the standards and sets the timeline for their implementation.

History of emission standards in India

Though India introduced emission standards in the year 1991, laws became more stringent only in 1996 when vehicle manufacturers were directed to install Catalytic converters to curtail exhaust emissions for petrol vehicles which led to the introduction of unleaded petrol in the market.

Later, the government notified fuel specifications with regard to environmental considerations that were to be implemented from 2000 onwards. According to this, the emission standards were to be on par with European regulations. Thus, it was mandatory for the BS-I and BS-II standards to comply with Euro I and Euro II respectively.

In 2005, BS-III norms were implemented in 13 major cities, while and BS-II standards were enforced in the rest of India. In 2010, BS-IV and BS-III fuel emission norms were imposed in a similar manner.

At present, BS IV is applicable in 33 major cities with the required grade of fuel being available, while BS III is applicable for the rest of India.

Roadmap to achieve emission norms-National Auto Fuel Policy 2003

-The National Auto Fuel Policy 2003 addresses the issues of vehicular emissions and vehicular technologies by applying fuel quality norms.

-It promoted the use of LPG/CNG for cities with high pollution.

-It also stipulated the timeline for implementation of emission standards across India. The policy included guidelines for auto fuels, reduction of pollution from older vehicles and R&D for air quality data creation and health administration.

-Recently, the government constituted an Expert Committee under the Chairmanship of Soumitra Choudhuri to draft Auto Fuel Vision and Policy 2025. The report was published in May 2014.

The recommendations of the Expert Committee are as follows:

-It has devised a road map for auto fuel quality till 2025 considering the achievement under the last Auto Fuel Policy, reduction in vehicular emissions currently in use, supply and availability of fuels.

-It recommended the nationwide fuel standards to be BS-IV from April 2017. It also proposed revision of fuel standards to BS V in 2020 and BS VI in 2024.

-It also suggested that refineries should be upgraded and highly equipped to produce BS-V grade petrol and diesel.

-Further, it proposed that a Special Fuel Upgradation Cess of 75 paise/litre be imposed on fuel purchases to meet upgradation costs.

Challenges in the implementation of BS-VI norms

Engine manufacturers:

Engine development firms have cited technological difficulties in implementing the changes stating that jumping directly to BS-VI norms (skipping BS-V which itself is time-consuming) would give them little time to design requisite changes in their vehicle parts.

Making the desired quality fuel is also a big task for the refineries as their upgradation will require large sums of money. Yet if the fuel is not uniformly available, then it would not be possible to achieve the objective of reducing pollution.

Auto manufacturers

Two major challenges lie ahead of auto firms that have to design vehicles that comply with the BS-VI norms:

a. Diesel Particulate Filter (DPF): The average size of cars in India provide lesser space to incorporate DPF which functions as an exhaust to remove particulate matter (majorly soot particles) generated from diesel. Also, driving speed in India is very less and hence it would be difficult to attain a temperature of 600° Celsius which is necessary for the DPF to burn soot particles. Thus, the optimisation of the DPF would be difficult.

b. Selective Catalytic Reduction Module: It reduces emission of nitrogen oxides. It needs injection of aqueous solution into the system, for which a separate infrastructure is required to ensure countrywide supply.


With a hope to achieve a clean environment and encourage the use of non-conventional energy sources, India has taken a few steps towards compliance with international regulations. This will promote a green environment and ensure good public health by improving overall air quality.