Bharat stage emission standards

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Bharat stage emission standards (BSES) are emission standards instituted by the Government of India to regulate the output of air pollutants from compression ignition engines and Spark-ignition engines equipment, including motor vehicles. The standards and the timeline for implementation are set by the Central Pollution Control Board under the Ministry of Environment, Forest and Climate Change.[1]

The standards, based on European regulations were first introduced in 2000. Progressively stringent norms have been rolled out since then. All new vehicles manufactured after the implementation of the norms have to be compliant with the regulations.[2] Since October 2010, Bharat Stage (BS) III norms have been enforced across the country. In 13 major cities, Bharat Stage IV emission norms have been in place since April 2010[3] and it has been enforced for entire country since April 2017. In 2016, the Indian government announced that the country would skip the BS V norms altogether and adopt BS VI norms by 2020.[4] In its recent judgment, the Supreme Court has banned the sale and registration of motor vehicles conforming to the emission standard Bharat Stage IV in the entire country from 1 April 2020.[5]

On 15 November 2017, the Petroleum Ministry of India, in consultation with public oil marketing companies, decided to bring forward the date of BS VI grade auto fuels in NCT of Delhi with effect from 1 April 2018 instead of 1 April 2020. In fact, Petroleum Ministry OMCs were asked to examine the possibility of introduction of BS VI auto fuels in the whole of NCR area from 1 April 2019. This huge step was taken due to the heavy problem of air pollution faced by Delhi which became worse around 2019. The decision was met with disarray by the automobile companies as they had planned the development according to roadmap for 2020.

The phasing out of 2-stroke engine for two wheelers, the cessation of production of the Maruti 800, and the introduction of electronic controls have been due to the regulations related to vehicular emissions.[6]

While the norms help in bringing down pollution levels, it invariably results in increased vehicle cost due to the improved technology and higher fuel prices. However, this increase in private cost is offset by savings in health costs for the public, as there is a lesser amount of disease-causing particulate matter and pollution in the air. Exposure to air pollution can lead to respiratory and cardiovascular diseases, which is estimated to be the cause for 6,20,000 early deaths in 2010, and the health cost of air pollution in India has been assessed at 3% of its GDP.[citation needed]

Motor vehicles[edit]

Comparison between European, US, and Bharat stage (Indian) emission standards for petrol passenger cars.
Comparison between European, US, and Bharat stage (Indian) emission standards for diesel passenger cars. The sizes of the green circles represent the limits for particulate matter.

To regulate the pollution emitted by cars and two-wheelers, the Government of India has placed forth regulations known as Bharat Stage Emission Standards (BSES). The Central Government has mandated that every vehicle manufacturer, each two-wheels and four-wheels, ought to manufacture, sell and register solely BS6 (BSVI) vehicles from 1 April 2020.

Both BSIV and BSVI area unit emission norms that set the most permissible levels for pollutants emitting from an automotive or a two-wheeler exhaust. Compared to the BS4, BS6 emission standards area unit stricter, whereas makers use this variation to update their vehicles with new options and safety standards, the largest or the numerous modification comes within the type of stricter permissible emission norms.[7]

The below table offers Associate in Nursing insight into the modification within the permissible emission levels of BS6 vehicles compared to BS4 vehicles:

Fuel Type Pollutant Gases BS6 (BSVI) BS4 (BSIV)
Petroleum Distillate Vehicle Nitrogen Oxide (NOx) Limit 60 mg 80 mg
Particulate Matter (PM) Limit 4.5 mg/km -
Diesel Fuel Vehicle Nitrogen Oxide (NOx) Limit 80 mg 250 mg
Particulate Matter (PM) Limit 4.5 mg/km 25 mg
HC + NOx 170 mg/km 300 mg

These area unit emission standards set by Bharat Safety Emission commonplace (BSEB) to manage the output of pollutants from vehicles plying on the road. The Central Pollution Control Board, under the Ministry of Environment, Forest and Climate Change (Mo.E.F.C.C.), sets the permissible pollution levels and timeline to implement an equivalent by vehicle makers.

The abbreviation of Bharat Stage is 'BS' and is suffixed with the iteration of the actual emission norms. The Indian emissions standards area unit supported the lines of European norms unremarkably called monetary unit a pair of, EURO 3, and so on. the primary rules with the soubriquet Asian nation 2000 were introduced in 2000, with the second and third iteration introduced in 2001 and 2005 with the soubriquet BSII (BS2) and BSIII (BS3), respectively.

The fourth iteration BSIV or BS4 was introduced in 2017, and therefore the delay between the introduction of BS3 and BS4 resulted in fast-tracking the BSVI or BS6 emission rather than BSV or BS5 norms. every of those emission norms has stricter emission standards compared to its predecessors.


The first emission norms were introduced in India in 1991 for petroleum distillate, and 1992 for diesel vehicles. These were followed by making the Catalytic converter mandatory for petrol vehicles and the introduction of unleaded petrol in the market.[8]

On 29 April 1999, the Supreme Court of India ruled that all vehicles in India have to meet Euro I or India 2000 norms by 1 June 1999 and Euro II will be imperative in the NCR by 1 April 2000. Car makers were not prepared for this transition and in a subsequent judgement the implementation date for Euro II was not enforced.[9][10]

In 2002, the Indian Government accepted the report submitted by the Mashelkar committee. The committee proposed a road map for the roll-out of Euro based emission norms for India. It also recommended a phased implementation of future norms with the regulations being implemented in major cities first and extended to the rest of the country after a few years.[11]

Based on the recommendations of the committee, the National Auto Fuel policy was announced officially in 2003. The roadmap for implementation of the Bharat stage norms were laid out until 2010. The policy also created guidelines for auto fuels, reduction of pollution from older vehicles and R&D for air quality data creation and health administration.[12]

Background information[edit]

Table 1: Indian emission standards (4-wheeled vehicles)
Standard Reference Year Region
India 2000 / Bharat Stage I Euro 1 2000 Nationwide
Bharat Stage II Euro 2 2001 NCR*, Mumbai, Kolkata, Chennai
2003 NCR*, 14 Cities†
2005 Nationwide
Bharat Stage III Euro 3 2005-04 NCR*, 14 Cities†
2010 Nationwide
Bharat Stage IV Euro 4 2010 NCR*, 14 Cities†
2017 Nationwide
Bharat Stage V Euro 5 (Skipped)
Bharat Stage VI Euro 6 2018 Delhi
2019 NCR*
2020 [13] Nationwide
* National Capital Region (Delhi)

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

The above standards apply to all new 4-wheeled vehicles sold and registered in the respective regions. In addition, the National Auto Fuel Policy introduces certain emission requirements for interstate buses with routes originating or terminating in Delhi or the other 10 cities.

Progress of emission standards for 2-and 3-wheeled vehicles:[14]

Table 2: Indian emission standards (2- and 3-wheeled vehicles)
Standard Reference Date
Bharat Stage II Euro 2 1 April 2000
Bharat Stage III Euro 3 1 April 2010
Bharat Stage IV Euro 4 1 April 2017
Bharat Stage VI Euro 6 1 April 2020 with mandate [15]

In order to comply with the BSIV norms, 2- and 3-wheeler manufacturers will have to fit an evaporative emission control unit, which should lower the amount of fuel that is evaporated when the motorcycle is parked.

Trucks and buses[edit]

Exhaust gases from vehicles form a significant portion of air pollution which is harmful to human health and the environment

Emission standards for new heavy-duty diesel engines—applicable to vehicles of GVW > 3,500 kg—are listed in Table 3.

Table 3: Emission standards for diesel truck and bus engines, g/kWh
Year Reference Test CO HC NOx PM
1992 ECE R49 17.3–32.6 2.7–3.7
1996 ECE R49 11.20 2.40 14.4
2000 Euro I ECE R49 4.5 1.1 8.0 0.36*
2005† Euro II ECE R49 4.0 1.1 7.0 0.15
2010† Euro III ESC 2.1 0.66 5.0 0.10
ETC 5.45 0.78 5.0 0.16
2010‡ Euro IV ESC 1.5 0.46 3.5 0.02
ETC 4.0 0.55 3.5 0.03
* 0.612 for engines below 85 kW

† Earlier introduction in selected regions, see Table 1. ‡ Only in selected regions, see Table 1.

More details on Euro I–III regulations can be found in the EU heavy-duty engine standards.

Light-duty diesel vehicles[edit]

Emission standards for light-duty diesel vehicles (GVW ≤ 3,500 kg) are summarised in Table 4. Ranges of emission limits refer to different classes (by reference mass) of light commercial vehicles; comparable to EU light-duty vehicle emission standards. The lowest limit in each range applies to passenger cars (GVW ≤ 2,500 kg; up to 6 seats).

Table 4: Emission standards for light-duty diesel vehicles, g/km
Year Reference CO HC HC+NOx NOx PM
1992 17.3–32.6 2.7–3.7
1996 5.0–9.0 2.0–4.0
2000 Euro 1 2.72–6.90 0.97–1.70 0.14–0.25
2005† Euro 2 1.0–1.5 0.7–1.2 0.08–0.17
2010† Euro 3 0.64
2010‡ Euro 4 0.50
† Earlier introduction in selected regions, see Table 1.

‡ Only in selected regions, see Table 1.

The test cycle has been the ECE + EUDC for low power vehicles (with maximum speed limited to 90 km/h). Before 2000, emissions were measured over an Indian test cycle.

Engines for use in light-duty vehicles can be also emission tested using an engine dynamo-meter. The respective emission standards are listed in Table 5.

Table 5: Emission standards for light-duty diesel engines, g/kWh
Year Reference CO HC NOx PM
1992 14.0 3.5 18.0
1996 11.20 2.40 14.4
2000 Euro I 4.5 1.1 8.0 0.36*
2005† Euro II 4.0 1.1 7.0 0.15
* 0.612 for engines below 85 kW

† Earlier introduction in selected regions, see Table 1.

Light-duty petrol vehicles[edit]

4-wheeled vehicles[edit]

Emissions standards for petrol vehicles (GVW ≤ 3,500 kg) are summarised in Table 6. Ranges of emission limits refer to different classes of light commercial vehicles (comparable to EU light-duty vehicle emission standards). The lowest limit in each range applies to passenger cars (GVW ≤ 2,500 kg; up to 6 seats).

Table 6: Emission standards for petrol vehicles (GVW ≤ 3,500 kg), g/km
Year Reference CO HC HC+NOx NOx
1991 14.3–27.1 2.0–2.9
1996 8.68–12.4 3.00–4.36
1998* 4.34–6.20 1.50–2.18
2000 Euro 1 2.72–6.90 0.97–1.70
2005† Euro 2 2.2–5.0 0.5–0.7
2010† Euro 3 2.3
2010‡ Euro 4 1.0
* For catalytic converter fitted vehicles.

† Earlier introduction in selected regions, see Table 1. ‡ only in selected regions, see Table 1.

Petrol vehicles must also meet an evaporative (SHED) limit of 2 g/test (effective 2000).

2- and 3-wheeled vehicles[edit]

Emission standards for 2- and 3-wheeled petrol vehicles are listed in the following tables.[16]

Table 7: Emission standards for 3-wheeled petrol vehicles, g/km
1991 12–30 8–12
1996 6.75 5.40
2000 4.00 2.00
2005 (BS II) 2.25 2.00
2010-04 (BS III) 1.25 1.25
Table 8: Emission standards for 2-wheeled petrol vehicles, g/km
1991 12–30 8–12
1996 5.50 3.60
2000 2.00 2.00
2005 (BS II) 1.5 1.5
2010-04 (BS III) 1.0 1.0
Table 9: Emission standards for 2- and 3-wheeled diesel vehicles, g/km
2005-04 1.00 0.85 0.10
2010-04 0.50 0.50 0.05

Overview of the emission norms in India[edit]

  • 1991 – Idle CO limits for petrol vehicles and free acceleration smoke for diesel vehicles, mass emission norms for petrol vehicles.
  • 1992 – Mass emission norms for diesel vehicles.
  • 1996 – Revision of mass emission norms for petrol and diesel vehicles, mandatory fitment of catalytic converter for cars in metros on unleaded petrol.
  • 1998 – Cold start norms introduced.
  • 2000 – India 2000 (equivalent to Euro I) norms, modified IDC (Indian driving cycle), Bharat Stage II norms for Delhi.
  • 2001 – Bharat Stage II (equivalent to Euro II) norms for all metros, emission norms for CNG and LPG vehicles.
  • 2003 – Bharat Stage II (equivalent to Euro II) norms for 13 major cities.
  • 2005 – From 1 April, Bharat Stage IV (equivalent to Euro IV[citation needed]) norms for 13 major cities.
  • 2010 – Bharat Stage IV emission norms for 2-wheelers, 3-wheelers and 4-wheelers for the entire country, whereas Bharat Stage IV (equivalent to Euro IV) for 13 major cities for only 4-wheelers. Bharat Stage IV also has norms on OBD (similar to Euro III but diluted).
  • 2017 – Bharat Stage IV norms for all vehicles.
  • 2018 - Bharat Stage VI fuel norms from 1 April 2018 in Delhi instead of 2020.[17]
  • 2020 – Bharat Stage VI fuel norms from 1 April 2020 nationwide switching India to world's cleanest diesel and petrol.[18]
  • 2023 - Bharat Stage VI Second Phase Fuel norms from 1 April 2023 have only Petrol also called RDE norms with e20 fuels.

CO2 emission[edit]

India's auto sector accounts for about 18% of the total CO2 emissions in the country. Relative CO2 emissions from transport have risen rapidly in recent years, but like the EU, currently there are no standards for CO2 emission limits for pollution from vehicles.

Technology Changes[edit]

Technology Changes In Petrol Engines[edit]

As per Bharat Stage-6 norms, the emission of carbon monoxide is to be reduced by 30% and NOx by 80%. The BS-6 norms also sets limits for Hydrocarbon and particulate emissions, which were not specified in earlier norms. To meet the emission requirements of Bharat Stage-6, the carburetors in petrol engines need to be replaced by the programmed fuel injectors. To further reduce tail pipe emissions, the exhaust system would be fitted with three way catalytic converters. The norms also mandates On-Board Diagnostic System (OBD) for all BS-6 compliant vehicles.[19]

Technology Changes In Diesel Engines[edit]

As per the Bharat Stage-6 norms, the NOx emissions from a diesel engines are to be reduced by 70% and particulates by 80%. To achieve this, the engines need to be equipped with Euro-6 compliant technologies. The major technical changes to associated with this are:

  1. Fitting Diesel Particulate Filters in exhaust system.
  2. Using Selective Catalytic Reduction (SCR) or Exhaust Gas Recirculation techniques to reduce NOx in emissions.
  3. An on-board diagnostic system required to monitor the malfunctioning of parts related to emissions[20]

Obligatory labelling[edit]

There is also no provision to make the CO2 emissions labelling mandatory on cars in the country. A system exists in the EU to ensure that information relating to the fuel economy and CO2 emissions of new passenger cars offered for sale or lease in the Community is made available to consumers to enable consumers to make an informed choice.

Non-road diesel engines[edit]

Construction machinery[edit]

Emission standards for diesel construction machinery were adopted on 21 September 2006. The standards are structured into two tiers:

  • Bharat (CEV) Stage II—These standards are based on the EU Stage I requirements, but also cover smaller engines that were not regulated under the EU Stage I.
  • Bharat (CEV) Stage III—These standards are based on US Tier 2/3 requirements.

The standards are summarised in the following table:

The limit values apply for both type approval (TA) and conformity of production (COP) testing. Testing is performed on an engine dynamo-meter over the ISO 8178 C1 (8-mode) and D2 (5-mode) test cycles. The Bharat Stage III standards must be met over the useful life periods shown in Table 11. Alternatively, manufacturers may use fixed emission deterioration factors of 1.1 for CO, 1.05 for HC, 1.05 for NOx, and 1.1 for PM.

Table 11: Bharat (CEV) Stage III useful life periods
Power rating Useful life period
< 19 kW 3,000
19–37 kW Constant speed 3,000
Variable speed 5,000
> 37 kW 8,000

Agricultural tractors[edit]

Emission standards for diesel agricultural tractors are summarised in Table 12.

Table 12: Bharat (Trem) emission standards for diesel agricultural tractors
Engine power Date CO HC HC+NOx NOx PM
kW g/kW⋅h
Bharat (Trem) Stage I
All 1999-10 14.0 3.5 - 18.0 -
Bharat (Trem) Stage II
All 2003-06 9.0 - 15.0 - 1.00
Bharat (Trem) Stage III
All 2005-10 5.5 - 9.5 - 0.80
Bharat (Trem) Stage III A
P < 8 2010-04 5.5 - 8.5 - 0.80
8 ≤ P < 19 2010-04 5.5 - 8.5 - 0.80
19 ≤ P < 37 2010-04 5.5 - 7.5 - 0.60
37 ≤ P < 56 2011-04 5.0 - 4.7 - 0.40
56 ≤ P < 75 2011-04 5.0 - 4.7 - 0.40
75 ≤ P < 130 2011-04 5.0 - 4.0 - 0.30
130 ≤ P < 560 2011-04 3.5 - 4.0 - 0.20

Emissions are tested over the ISO 8178 C1 (8-mode) cycle. For Bharat (Trem) Stage III A, the useful life periods and deterioration factors are the same as for Bharat (CEV) Stage III, Table 11.

Electricity generation[edit]

Generator sets[edit]

Emissions from new diesel engines used in generator sets have been regulated by the Ministry of Environment and Forests, Government of India [GSR 371 (E), 17 May 2002]. The regulations impose type approval certification, production conformity testing and labelling requirements. Certification agencies include the Automotive Research Association of India (ARAI) and the Vehicle Research and Development Establishment (VRDE). The emission standards are listed below.

Table 13: Emission standards for diesel engines ≤ 800 kW for generator sets
Engine power (P) Date CO HC NOx PM Smoke
g/kWh 1/m
P ≤ 19 kW 2004-01 5.0 1.3 9.2 0.6 0.7
2005-07 3.5 1.3 9.2 0.3 0.7
19 kW < P ≤ 50 kW 2004-01 5.0 1.3 9.2 0.5 0.7
2004-07 3.5 1.3 9.2 0.3 0.7
50 kW < P ≤ 176 kW 2004-01 3.5 1.3 9.2 0.3 0.7
176 kW < P ≤ 800 kW 2004-11 3.5 1.3 9.2 0.3 0.7

Engines are tested over the 5-mode ISO 8178 D2 test cycle. Smoke opacity is measured at full load.

Table 14: Emission limits for diesel engines > 800 kW for generator sets
mg/N⋅m3 mg/N⋅m3 ppm(v) mg/N⋅m3
Until 2003-06 150 150 1100 75
2003-07 – 2005-06 150 100 970 75
2005-07 150 100 710 75

Concentrations are corrected to dry exhaust conditions with 15% residual O2.

Power plants[edit]

The emission standards for thermal power plants in India are being enforced based on Environment (Protection) Act, 1986 of Government of India and its amendments from time to time.[21] A summary of emission norms for coal- and gas-based thermal power plants is given in Tables 15 and 16.

Table 15: Environmental standards for coal- and gas-based power plants
Capacity Pollutant Emission limit
Coal based thermal plants
Below 210 MW Particulate matter (PM) 350 mg/N⋅m3
210 MW and above   150 mg/N⋅m3
500 MW and above   50 mg/N⋅m3
Gas based thermal plants
400 MW and above NOX(V/V at 15% excess oxygen) 50 PPM for natural gas; 100 PPM for naphtha
Below 400 MW and up to 100 MW   75 PPM for natural gas; 100 PPM for naphtha
Below 100 MW   100 PPM for naphtha/natural gas
For conventional boilers   100 PPM
Table 16: Stack height requirement for SO2 control
Power generation capacity Stack height (m)
Less than 200/210 MWe H = 14 (Q)0.3 where Q is emission rate of SO2 in kg/h,
H = Stack height in metres
200/210 MWe or less than 500 MWe 200 200
500 MWe and above 275 (+ Space provision for FGD systems in future)

The norm for 500 MW and above coal-based power plant being practised is 40 to 50 mg/N⋅m and space is provided in the plant layout for super thermal power stations for installation of flue gas desulfurisation (FGD) system. But FGD is not installed, as it is not required for low sulphur Indian coals while considering SOx emission from individual chimney.

In addition to the above emission standards, the selection of a site for a new power plant has to maintain the local ambient air quality as given in Table 17.

Table 17: Ambient air quality standard
Category Concentration (g/m3)
Industrial and mixed-use 500 120 5,000 120
Residential and rural 200 80 2,000 80
Sensitive 100 30 1,000 30
Table 18: World Bank norms for new projects
Existing air quality Recommendation
SOx > 100 μg/m3 No project
SOx = 100 μg/m3 Polluted area, max from a project 100 t/day
SOx < 50 μg/m3 Unpolluted area, max from a project 500 t/day

However the norms for SOx are even stricter for selection of sites for World Bank funded projects (refer Table 18). For example, if SOx level is higher than 100 μg/m3, no project with further SOx emission can be set up; if SOx level is 100 μg/m3, it is called polluted area and maximum emission from a project should not exceed 100 t/day; and if SOx is less than 50 μg/m3, it is called unpolluted area, but the SOx emission from a project should not exceed 500 t/day. The stipulation for NOx emission is that its emission should not exceed 260 g of NOx/GJ of heat input.

In view of the above, it may be seen that improved environment norms are linked to financing and are being enforced by international financial institutions and not by the policies/laws of land.


Fuel quality plays a very important role in meeting the stringent emission regulation.

The fuel specifications of petrol and diesel have been aligned with the Corresponding European Fuel Specifications for meeting the Euro II, Euro III and Euro IV emission norms.

The BS IV grade fuel was introduced in 2010 and is available in 39 cities, as reported in 2016. The rest of the country has to make do with BS III fuel.[22]

The use of alternative fuels has been promoted in India both for energy security and emission reduction. Delhi and Mumbai have more than 100,000 commercial vehicles running on CNG fuel. Delhi has the largest number of CNG commercial vehicles running anywhere in the World. India is planning to introduce Bio-diesel, ethanol petrol blends in a phased manner and has drawn up a road map for the same. The Indian auto industry is working with the authorities to facilitate for introduction of the alternative fuels. India has also set up a task force for preparing the Hydrogen road map. The use of LPG has also been introduced as an auto fuel and the oil industry has drawn up plans for setting up of auto LPG dispensing stations in major cities.

Indian petrol specifications[edit]

Table 19: Indian petrol specifications
Serial no. Characteristics Unit BS 2 BS 3 BS 4 BS 6 BS 7
1 Density 15 °C kg/m3 710–770 720–775 720–775 720-775
2 Distillation
3 a) Recovery up to 70 °C (E70)
b) Recovery up to 100 °C (E100)
c) Recovery up to 180 °C (E180)
d) Recovery up to 150 °C (E150)
e) Final boiling point (FBP), max
f) Residue max
% volume
% volume
% volume
% volume
% volume
75 min
75 min
4 Research Octane Number (RON), min 88 91 91
5 Anti-Knock Index (AKI)/ MON, min 84 (AKI) 81 (MON) 81 (MON)
6 Sulphur, total, max % mass 500 mg/kg 150 mg/kg 50 mg/kg 10 mg/kg
7 Lead content (as Pb), max 200  61.05 2.005 16.005
8 Reid vapour pressure (RVP), max kPa 35–60 60 60
9 Benzene content, max
a) For metros
b) For the rest
% volume -
1 1
10 Olefin content, max % volume - 21 21
11 Aromatic content, max % volume - 42 35<

Indian diesel specifications[edit]

Table 20: Indian diesel specifications
Serial no. Characteristic BS II BS III BS IV BS V BS VI
1 Density kg/m3 15 °C 820-800 820–845 820–845
2 Sulphur content mg/kg max 500 350 50 10 10
Cetane number minimum and / or
Cetane index
4 Polycyclic aromatic hydrocarbon - 11 11
Reco min at 350 °C
Reco min at 370 °C
95% vol. reco at 0 °C



Diesel fuel quality in India[edit]

Table 21: Diesel fuel quality in India
Date Particulars
1995 Cetane number: 45; Sulphur: 1%
1996 Sulphur: 0.5% (Delhi + selected cities)
1998 Sulphur: 0.25% (Delhi)
1999 Sulphur: 0.05% (Delhi, limited supply)
2000 Cetane number: 48; Sulfur: 0.25% (Nationwide)
2001 Sulphur: 0.05% (Delhi + selected cities)
2005 Sulphur: 350 ppm (Euro 3; selected areas)
2010 Sulphur: 350 ppm (Euro 3; nationwide)
2016 Sulphur: 50 ppm (Euro 4; major cities)
2017 Sulphur: 50 ppm (Euro 4; nationwide)
2020 Sulphur: 10ppm (Euro 6; entire country)

Indian bio-diesel specifications[edit]

Table 22: Indian bio-diesel specifications
Serial no. Characteristics Requirement Method of test, ref. to
    Other methods [P:] of IS 1448
(1) (2) (3) (4) (5)
i. Density at 15 °C, kg/m3 860–900 ISO 3675 P:16/
    ISO 12185 P:32
ii. Kinematic viscosity at 40 °C, cSt 2.5–6.0 ISO 3104 P:25
iii. Flash point (PMCC) °C, min 120 P:21
iv. Sulphur, mg/kg max 50.0 ASTM D 5453 P:83
v Carbon residue (Ramsbottom)*, % by mass, max 0.05 ASTM D 4530ISO 10370 -
vi. Sulfated ash, % by mass, max 0.02 ISO 6245 P:4
vii. Water content, mg/kg, max 500 ASTM D 2709 P:40
    ISO 3733
    ISO 6296
viii Total contamination, mg/kg, max 24 EN 12662 -
ix Cu corrosion, 3 h at 50 °C, max 1 ISO 2160 P:15
x Cetane no., min 51 ISO 5156 P:9
xi Acid value, mg KOH/g, max 0.50 - P:1 / Sec 1
xii Methanol @, % by mass, max 0.20 EN 14110 -
xiii Ethanol, @@ % by mass, max 0.20 -
xiv Ester content, % by mass, min 96.5 EN 14103 -
xv Free glycerol, % by mass, max 0.02 ASTM D 6584 -
xvi Total glycerol, % by mass, max 0.25 ASTM D 6584 -
xvii Phosphorus, mg/kg, max 10.0 ASTMD 4951 -
xviii Sodium and Potassium, mg/kg, max To report EN 14108 & -
      EN 14109 -
xix Calcium and magnesium, mg/kg, max To report ** -
xx Iodine value To report EN 14104 -
xxi Oxidation stability, at 110 °C h, min 6 EN 14112 -
* Carbon residue shall be run on 100% sample

** European method is under development
@ Applicable for Fatty Acid Methyl Ester
@@ Applicable for Fatty Acid Ethyl Ester

Criticism and commentary[edit]

Ineffectiveness of present pollution control system[edit]

Presently, all vehicles need to undergo a periodic emission check (3 months/ 6 months/ 1 year) at PUC centres, fuel stations and private garages which are authorized to check the vehicles. In addition, transport vehicles need to undergo an annual fitness check carried out by RTOs for emissions, safety and road-worthiness.

The objective of reducing pollution is not achieved to a large extent by the present system. Some reasons for this are:

  • Independent centers do not follow rigorous procedures due to inadequate training
  • Equipment not subjected to periodic calibration by independent authority
  • Lack of professionalism has led to malpractice
  • Tracking system of vehicles failing to meet norms non-existent
  • The website for testing petrol/LPG/CNG vehicles does not have the CO-corrected formula specified by ARAI. Due to this omission, many vehicles with high CO emissions pass the pollution check

Comparison between Bharat stage and Euro norms[edit]

The Bharat stage norms have been styled to suit specific needs and demands of Indian conditions. The differences lie essentially in environmental and geographical needs, even though the emission standards are exactly the same.

For instance, Euro III is tested at sub-zero temperatures in European countries. In India, where the average annual temperature ranges between 24 and 28 °C, the test is done away with.

Another major distinction is in the maximum speed at which the vehicle is tested. A speed of 90 km/h is stipulated for BS III, whereas it is 120 km/h for Euro III, keeping emission limits the same in both cases

In addition to limits, test procedure has certain finer points too. For instance, the mass emission test measurements done in g/km on a chassis dynamometer requires a loading of 100 kg weight in addition to unloaded car weight in Europe. In India, BS III norms require an extra loading of 150 kg weight to achieve the desired inertia weight mainly due to road conditions here.[23]

Non-existence of CO2 limits[edit]

Various groups and agencies have criticized the government and urged the government of India to draft mandatory fuel efficiency standards for cars in the country, or at least to make the CO2 emissions labelling mandatory on all new cars in the country. The auto companies should inform the customers about a vehicle's emissions.[24]

Cycle beating[edit]

For the emission standards to deliver real emission reductions it is crucial that the test cycles under which the emissions have to comply as much as possible reflect normal driving situations. It was discovered that manufacturers of engine would engage in what was called 'cycle beating' to optimize emission performance to the test cycle, while emissions from typical driving conditions would be much higher than expected, undermining the standards and public health. In one particular instance, research from two German technology institutes found that for diesel cars no 'real' NOx reductions have been achieved after 13 years of stricter standards.[25]

Regulatory framework[edit]

In India, the rules and regulations related to driving licenses, registration of motor vehicles, control of traffic, construction and maintenance of motor vehicles, etc. are governed by the Motor Vehicles Act 1988 (MVA) and the Central Motor Vehicles rules 1989 (CMVR). The Ministry of Shipping, Road Transport & Highways (MoSRT&H) acts as a nodal agency for formulation and implementation of various provisions of the Motor Vehicle Act and CMVR.[26]

To involve all stake holders in regulation formulation, MoSRT&H has constituted two Committees to deliberate and advise Ministry on issues relating to Safety and Emission Regulations, namely –

  • CMVR- Technical Standing Committee (CMVR-TSC)
  • Standing Committee on Implementation of Emission Legislation (SCOE)

CMVR- Technical Standing Committee (CMVR-TSC)[edit]

This Committee advises MoSRT&H on various technical aspects related to CMVR. This committee has representatives from various organisations namely; Ministry of Heavy Industries & Public Enterprises (MoHI&PE)), MoSRT&H, Bureau Indian Standards (BIS), Testing Agencies such as Automotive Research Association of India (ARAI), International Centre for Automotive Technology (ICAT -, Vehicle Research Development & Establishment (VRDE), Central Institute of Road Transport (CIRT), industry representatives from Society of Indian Automobile Manufacturers (SIAM), Automotive Component Manufacturers Association (ACMA) and Tractor Manufacturers Association (TMA) and representatives from State Transport Departments. Major functions the committee are:

  • To provide technical clarification and interpretation of the Central Motor Vehicles Rules having technical bearing, to MoRT&H, as and when so desired.
  • To recommend to the Government the International/ foreign standards which can be used in lieu of standard notified under the CMVR permit use of components/parts/assemblies complying with such standards.
  • To make recommendations on any other technical issues which have direct relevance in implementation of the Central Motor Vehicles Rules.
  • To make recommendations on the new safety standards of various components for notification and implementation under Central Motor Vehicles Rules.
  • To make recommendations on lead time for implementation of such safety standards.
  • To recommend amendment of Central Motor Vehicles Rules having technical bearing keeping in view of Changes in automobile technologies.

CMVR-TSC is assisted by another Committee called the Automobile Industry Standards Committee (AISC) having members from various stakeholders in drafting the technical standards related to Safety. The major functions of the committee are as follows:

  • Preparation of new standards for automotive items related to safety.
  • To review and recommend amendments to the existing standards.
  • Recommend adoption of such standards to CMVR Technical Standing Committee
  • Recommend commissioning of testing facilities at appropriate stages.
  • Recommend the necessary funding of such facilities to the CMVR Technical Standing Committee, and
  • Advise CMVR Technical Standing Committee on any other issues referred to it

The National Standards for Automotive Industry are prepared by Bureau of Indian Standards (BIS). The standards formulated by AISC are also converted into Indian Standards by BIS. The standards formulated by both BIS and AISC are considered by CMVR-TSC for implementation.

Standing Committee on Implementation of Emission Legislation (SCOE)[edit]

This Committee deliberates the issues related to implementation of emission regulation. Major functions of this committee are –

  • To discuss the future emission norms
  • To recommend norms for in-use vehicles to MoSRT&H
  • To finalise the test procedures and the implementation strategy for emission norms
  • Advise MoSRT&H on any issue relating to implementation of emission regulations.

Based on the recommendations from CMVR-TSC and SCOE, MoSRT&H issues notification for necessary amendments / modifications to the Central Motor Vehicle Rules.

In addition, the other Ministries like Ministry of Environment & Forest (MoEF), Ministry of Petroleum & Natural Gas (MoPNG) and Ministry of Non-conventional Energy Sources are also involved in formulation of regulations relating to Emissions, Noise, Fuels and Alternative Fuel vehicles.

See also[edit]


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  4. ^ "Post odd-even: India to skip Bharat Stage-V, to implement Stage-VI emission norms from 2020". 15 January 2016. Retrieved 17 December 2018.
  5. ^ Rajagopal, Krishnadas (24 October 2018). "SC bans sale of BS-IV vehicles from 2020". Retrieved 17 December 2018.
  6. ^ "Reforming the little rascal". The Indian Express. 29 July 1999.[permanent dead link]
  7. ^ "In this article, you may study BS4 vs BS6 engine, major variations and performance of the new BS6 engine". Archived from the original on 29 January 2020. Retrieved 10 January 2020.
  8. ^ "Ministry of Road Transport & Highways". Retrieved 17 December 2018.
  9. ^ "SC dilutes Euro norms". The Indian Express. 15 May 1999. Archived from the original on 29 January 2004.
  10. ^ "Maruti board on a junket as market share falls". The Indian Express. 31 July 1999. Archived from the original on 26 January 2013.
  11. ^ "Nod for recommendations on auto fuel policy". The Hindu. 9 January 2002. Archived from the original on 25 January 2013.
  12. ^ "National Auto Fuel Policy Announced" (Press release). 6 October 2003. Archived from the original on 10 March 2004.
  13. ^ Press Trust of India [@PTI_News] (6 January 2016). "Govt decides to skip BS-V; leapfrog to BS-VI emission norms by April 1, 2020: Transport Minister Nitin Gadkari" (Tweet) – via Twitter.
  14. ^ "Emission Standards: India: On-Road Vehicles and Engines". Retrieved 29 June 2009.
  15. ^ "Amid lockdown, India switches to BS-VI emission norms". The Hindu. 2 April 2020.
  16. ^ "Vehicular Technology in India | Emission Norms". SIAM India. Archived from the original on 11 June 2009. Retrieved 29 June 2009.
  17. ^ "BS-VI fuel norms from April 1, 2018 in Delhi instead of 2020". 15 November 2017. Retrieved 17 December 2018.
  18. ^ "Oil firms ready for BS-VI roll out: IOCL chairman Sanjiv Singh". The New Indian Express. 20 February 2020. Archived from the original on 28 February 2020. Retrieved 18 March 2023.
  19. ^ |title=Technology changes in BS6 petrol engines| |accessdate=2 February 2020
  20. ^ |url= |title=Technology changes in BS6 petrol engines| |accessdate=2 February 2020
  21. ^ Emission standards for power plants[dead link]
  22. ^ Karunakaran, Naren (26 April 2016). "Hasty introduction of Euro VI fuel norms triggers a slugfest between automakers, oil companies". The Economic Times/The Times of India. Retrieved 3 July 2016.
  23. ^ Abhishek Sengupta (20 February 2005). "TOI article on Bharat Stage norms". The Times of India. Retrieved 2 February 2011.
  24. ^ Pratyush (9 January 2008). "Greenpeace urges government for CO2 limits". Archived from the original on 13 July 2011. Retrieved 2 February 2011.
  25. ^ "T&E Bulletin, March 2006" (PDF). Retrieved 2 February 2011.
  26. ^ "Emission regulatory framework in India". Archived from the original on 27 January 2011. Retrieved 2 February 2011.

Further reading[edit]