Knowledge Nugget: No entry for Non-BS-VI vehicles in Delhi. Why understanding BS norms matters for UPSC Exam

Why in the news?

Last month, the Delhi government barred non-BS VI private vehicles registered outside Delhi from entering the Capital, and announced that pumps in the city will sell fuel to only those who possess a valid Pollution Under Control Certificate (PUCC) for their vehicles. As per the latest data, there are 41,10,585 end-of-life two-wheelers that are pre-Bharat Stage (BS), BS-I and BS-II, and 25,42,807 cars and other types of vehicles that are BS-III.

In today’s Knowledge Nugget, let’s understand the BS norms and how BS-VI implementation is going to tackle emissions from vehicles.

Key takeaways:

1. Bharat Stage emission norms are India’s standards for regulating pollution from motor vehicles. They set legal limits on exhaust emissions of pollutants such as carbon monoxide, hydrocarbons, nitrogen oxides and particulate matter. Each successive BS tightens these limits, pushing manufacturers to adopt cleaner engine technologies, better exhaust treatment systems and cleaner fuel.

2. India introduced emission norms first in 1991, and tightened them in 1996, when most vehicle manufacturers had to incorporate technology upgrades like catalytic converters to cut exhaust emissions. Fuel specifications based on environmental considerations were notified first in April 1996 — to be implemented by 2000, and incorporated in BIS 2000 standards.

3. Following the landmark Supreme Court order of April 1999, the Centre notified Bharat Stage-I (BIS 2000) and Bharat Stage-II norms, broadly equivalent to Euro I and Euro II, respectively. BS-II was for the National Capital Region and other metros; BS-I for the rest of India.

4. From April 2005, in line with the Auto Fuel Policy of 2003, BS-III and BS-II fuel quality norms came into existence for 13 major cities, and for the rest of the country, respectively. From April 2010, BS-IV and BS-III norms were put in place in 13 major cities and the rest of India, respectively.

5. The BS IV norms had been enforced across the country since April 2017. In 2016, the Centre had announced that the country would skip the BS-V norms altogether and adopt BS-VI norms by 2020.

6. Major emissions governed under these norms are carbon monoxide emissions, hydrocarbon emission limits. Nitrogen Oxides and particulate matter are also significant metrics. Furthermore, for every step up in standards, an improved standard of fuel is required. For BS-IV compliant vehicles, BS-IV standard fuel is required.

Air Pollution in NCR (File image)

7. The internal combustion engines in pre-BS IV vehicles lack effective exhaust-cleaning systems altogether while BS-IV vehicles rely largely on basic oxidation catalysts that offer only limited control over fine particulate emissions.

8. The main difference between BS-IV and BS-VI (which is comparable to Euro 6) is in the amount of sulphur in the fuel. BS-VI fuel is estimated to bring around an 80% reduction in sulphur content — from 50 parts per million (ppm) to 10 ppm.

9. Under the BS-VI regime, full modern exhaust after-treatment systems (technologies fitted to a vehicle’s exhaust), such as diesel particulate filters (DPFs) and selective catalytic reduction (SCR) units, are mandatory. These systems function as filters and chemical reactors within the exhaust stream, breaking down or trapping harmful gases and particles before they are released into the air.

10. For instance, catalytic converters convert toxic gases such as carbon monoxide and nitrogen oxides into less harmful substances like carbon dioxide, nitrogen and water vapour, while DPFs physically trap fine soot particles emitted by diesel engines, cutting particulate matter emissions by over 90%. Hence, BS VI vehicles can significantly reduce particulate matter emissions, as well as other emissions.

11. Delhi has historically implemented stricter emission norms earlier than the rest of the country due to its persistent air pollution problem. BS II norms were introduced in the Capital in 2001, BS III in 2005 and BS IV in 2010 – all several years before the nationwide rollout, as per the Central Pollution Control Board.

BEYOND THE NUGGET: Commission for Air Quality Management (CAQM)

1. The Commission was constituted through the CAQM Act, 2021, which came into force in the same year on April 13.

2. The air quality monitoring body is tasked with better coordination, research, identification, and resolution of problems surrounding the air quality index and related matters in NCR and adjoining areas. It has the power to take measures, issue directions and entertain complaints to protect and improve the air quality in the region.

3. The Commission is required to have a full-time chairperson with experience of not less than 15 years in the field of environmental protection and pollution control, or administrative experience of not less than 25 years.

Post Read Question

Consider the following statements about the Bharat Stage (BS) norms:

1. India first implemented the BS norms in 2000.

2. The use of non-BS VI vehicles is banned all over India.

3. The Sulphur content under BS-IV is maximum permissible at 80 Parts Per Million (ppm).

Which of the statements mentioned above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1, 2 and 3

(d) None of the above

(Sources: What is BS-IV emission standard?, BS-VI emission norms for vehicles: So near and yet so far, here is why, Here’s how to check if Delhi’s new pollution curbs will stop your vehicle, Why air pollution needs a long-term solution, not a reactive approach)

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