Friday, 12 December 2014 04:08




Emission standards set specific limits to the amount of pollutants that can be released into the environment. These focus on regulating pollutants released by automobiles (motor cars) and other powered vehicles.  The standards generally regulate the emissions of nitrogen oxides (NO2), sulphur oxides, particulate matter (PM) or soot, carbonmonoxide (CO), or volatile  hydrocarbons.

Bharat Stage Emission norms are a set of norms and rules instituted by the government of India which set the guidelines for the permissible emission levels. The Emission norms are classified under category of vehicles i.e. Commercial Vehicle, Passenger Vehicle, Light Duty , Heavy Duty Vehicle, etc. & further classified under Diesel & Petrol (Gasoline) engine.


• Vehicular Technology

• Fuel Quality

• Inspection & Maintenance of In-Use Vehicles

• Road and Traffic Management

The significant environmental implications of vehicles cannot be denied. The need to reduce vehicular pollution has led to emission control norms in conjunction with increasingly environment-friendly technologies.

The first State emission norms came into force in 1991 for Petrol vehicles and in 1992 for Diesel vehicles. From April 1995, fitting of catalytic converters in new Petrol driven passenger cars was mandated in the four Metros and introduction of unleaded petrol occurred in the market. Availability of ULP (unleaded petrol) was further extended to 42 major cities and now it is available throughout the country. This led to the reduction of pollution by 85% in petrol driven and by 61% in diesel vehicles according to 1991 levels.

Since the year 2000, India had adopted European emission and fuel regulations norms for four-wheeled light-duty and for heavy-duty vehicles.

Bharat Stage-II emission norms, which are akin to Euro-II norms have been introduced in National Capital Region (NCR) for passenger vehicles upto GVW 3.5T in 2000 and for heavier vehicles in 2001 in National Capital Territory (NCT) of Delhi.

These norms have further been extended to Agra, Ahmedabad, Bangalore, Hyderabad / Secundrabad, Kanpur, Pune and Surat, Lucknow and Sholapur in 2003.

The transport vehicles plying on inter-State permits or on National Permits or on All India Tourist Permits or plying from these cities to the other regions of the respective States have been exempted.

Basically Bharat Stage-II norms involve supply of Petrol and Diesel with 0.05% sulphur content. Similarly, Sulphur content in diesel has been reduced in the country, from a level of 1.0% in 1996 to 0.25% in 2000.

Bharat Stage-III emission norms have been introduced in 2005 with respect to Four Wheeled vehicles manufactured on and from 1st April, 2005 in the National Capital Region and the cities of Mumbai, Kolkata, Chennai, Bangalore, Hyderabad including Secundrabad, Ahmedabad, Pune, Surat, Kanpur and Agra except for four wheeled transport vehicles plying on Inter-State Permits or National Permits or All India Tourist Permits within the jurisdiction of these cities.

In addition to petrol and diesel, CNG and LPG are permitted to be used as auto fuels.

Bharat Stage-IV emission norms, Recently India has launched Bharat stage IV norms to control the vehicular pollution. BS 4 will be applicable to NCR (National Capital Territory) (Delhi) and other 10 cities Mumbai, Kolkata, Chennai, Bengaluru, Hyderabad, Ahmedabad, Pune, Surat, Kanpur and Agra, BS-III norms will be applicable to rest of India. These emission norms depend on the sulphur content in the diesel and petrol.

The difference between BS3 and BS4 are as follows:



Carbon Monoxide 2.30 g/km

Carbon Monoxide 1.00 g/km

HC 0.20 g/km

HC 0.10 g/km

NOx 0.15 g/km

NOX 0.08g/km

The emission norms are being revised with the standarized international emission norms. Enforcement, however, is sadly lacking, and there may be improvements by accrediting private sector institutions to complement the responsible governmental agencies. The Ministry has taken several steps in this direction. Workshop-cum-training programmes are organized every year (two each at ARAI, Pune and IIP, Dehradun). In these workshops, officers of the State Transport Department are given training regarding checking of vehicular pollution more scientifically and effectively. Under the Motor Vehicles Act, the authorized testing stations issue certificate of fitness for transport vehicles