National Ambient Air Quality Standards (NAAQS)

The NAAQS have been revisited and revised in November 2009 for 12 pollutants, which include

1-8 are measured on Air Quality Index while 9-12 are not considered in AQI

NOTE: No Co2, CFC, HCFC

National Air Quality Index AQI

Previously, Central Pollution Control Board along with State Pollution Control Boards has been operating National Air Monitoring Program (NAMP)
Defects of NAMP

Quality of data from some cities remains weak
standards set for pollutants fall short of World Health Organization recommendations.
Complex parameters difficult for common man to understand
Only 3 parameters included

AQI levels - 6 - Good, Satisfactory, Moderately Polluted, Poor, Very Poor, Critical
Pollutants considered -8-PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Lead [Note: Co2 is not present]
Short term National Ambient Air Quality Standards prescribed.
One Number- One Colour-One Description for the common man to judge the air quality within his vicinity.
Based on the measured ambient concentrations, corresponding standards and likely health impact, a sub-index is calculated for each of these pollutants. The worst sub-index reflects overall AQI

AQI		Associated Health Impacts
Good (0–50)	Green	Minimal Impact
Satisfactory (51–100)	Yellow	May cause minor breathing discomfort to sensitive people.
Moderately polluted (101–200)	Orange	May cause breathing discomfort to people with lung disease such as asthma, and discomfort to people with heart disease, children and older adults.
Poor (201–300)	Red	May cause breathing discomfort to people on prolonged exposure, and discomfort to people with heart disease
Very Poor (301–400)	Purple	May cause respiratory illness to the people on prolonged exposure. Effect may be more pronounced in people with lung and heart diseases.
Severe (401-500)	Maroon	May cause respiratory impact even on healthy people, and serious health impacts on people with lung/heart disease. The health impacts may be experienced even during light physical activity.

MoEFCC released four Color Classification of Industrial sectors based on Pollution Index PI

Red	Severe Polluting	PI >= 60	Total 60 industries including sugar, thermal power plants, paints
Orange	Moderately Polluting	PI 41 -59	Total 83 industries like coal, washeries and automobile servicing
Green	Low polluting	PI 21 -40
White	Non-polluting	PI <= 20	Exempted from requirement of environmental clearance

1. Scale of Industrial activity Observed Value of Pollution in air

2. Scale of exceedance of Environment quality.

3. Health related statistics.

4. Compliance status of Industry

Derived from Euro Emission Standards but with 5 year lag i.e. BS standards are five year later than the Euro standards
These are norms instituted by the government to regulate the output of air pollutants from internal combustion engine equipment, including motor vehicles.
The standards and the timeline for implementation are set by the CPCB under MoEFCC
Typically, the higher the stage, the more stringent the norms.
BS I (India 2000), BS II(2005), BS III(2010),BS-IV (2017), BS-V (2019 proposed) and BS-VI (2024 proposed) standards.
BS-IV

From April 2017, India made BS-IV mandatory
Less Sulphur, CO, Nox emissions
The BS-IV compliant fuels have Sulphur concentration of 50 parts per million (ppm).

For Diesel engines, the CO emission slashed by 60% and for Hydro carbons, Nox, slashed by 50%
For petrol engines, the CO emission slashed by 20% and for Hydro carbons, Nox, slashed by 50%
For motor vehicles, the CO emission slashed by 25% and for Hydro carbons, Nox, slashed by 40-50%
NOTE: No emission of SO2 in exhaust

It will be used for BS-V emission standard
It is a cylinder mounted vertically in engine compartment
It removes Particulate Matter/soot from the diesel exhaust.
It needs temperature of 600 degree Celsius to function, difficult in Indian conditions.

BS V - In 2016, GOI announced that the country would skip the BS-V norms altogether and adopt BS-VI norms by 2020.
BS VI

By moving to BS-VI, the country will be using the highest specifications of fuel standard available in the world right now.
The main difference between BS-IV and BS-VI is in the amount of sulphur and NOx in the fuel.
80% reduction in sulphur content — from 50 part per million (ppm) to 10 ppm.
NOx emissions

India is planning to country-wide rollout of BS-VI on 1st April 2020 (It is already introduced in NCR region from 1st April 2018)
However, in the wake of COVID-19, Supreme Court relaxes deadline of Mar 31, 2020 for sale and registration of BS-IV emission norm compliant vehicles

Corporate Average Fuel Efficiency (CAFE) norms
From 1 April 2017, India adopts CAFE, or corporate average fuel efficiency, norms, which require cars to be 30% or more fuel efficient from 2022 and 10% or more between 2017 and 2021
The mileage improvement will be decided on the basis of litres of fuel consumed by a vehicle to run 100km.
The move is targeted at reducing the carbon footprint of the automobile industry.
It is the first time such norms have been introduced in India.
CAFE norms are widely used in US