The Indian Supreme Court has ordered to ban the sale of vehicles with BSIII emission standards which is India’s own Standard for vehicles, as some Indian cities are ranked regularly among the dirtiest air in the world, that causing breathing and lung issues of most population. The Environment Pollution Control Authority (EPCA) had announced last year that vehicles less than BS-IV emission standard will not be registered after 1st April 2017.
The difference between BS3 standard & BS4 standard is the emission of carbon particulate matter, a major air pollutant that harm human health. While BS-3 vehicles emit 2.30gm of carbon monoxide per kg of fuel, the emission drops to 1gm per kg in BS-4 vehicles. Transition to BS-IV could lead to a substantial drop in particulate matter emissions. Similarly, hydrocarbon and nitrogen oxide emissions could drop between 41 and 80%, depending on the engine size.