Transport Department Govt. of NCT of Delhi

Pollution in Delhi
Emission Standards
Effects of pollution
Puc certificates
Pollution checking centres
Compressed natural gas
Steps for pollution checking

Vehicular Pollution in Delhi

Delhi 's registered vehicular population has nearly doubled to 4.5 million from 2.2 million in 1994, registering a growth rate of 10% per annum. About two-Third of the Motor Vehicles are two-wheelers.

Vehicular pollution is considered to be a major source of air pollution in Delhi . As per Central Pollution Control Board, the vehicular pollution load in Delhi increased by nearly 50% in 1995-96 from 1990-91. However, a decrease has been witnessed in recent years with the implementation of several control measures.  Vehicular emission load reported by the Central Pollution Control Board is under :


Pollution load (in ton/day)

Carbon Monoxide 421.84
Hydrocarbons 184.37
Nitrogen oxides 110.45

Particulate Mater


Total Pollution Load


Know the Exhaust Emission Standards

The pollution standards for in use vehicles have been prescribed under Rule 115(2) of Central Motor vehicles Rules, 1989. They are:


S. No.

Vehicle Type



HC (n-hexane equivalent) ppm


2&3-Wheelers (2/4-stroke) (Vehicles manufactured on and before 31st March,2000)




2&3-Wheelers (2-stroke) (Vehicles manufactured after 31st March,2000)




2&3-Wheelers (4-stroke) (Vehicles manufactured after 31st March,2000)




4-wheelers manufactured as per pre Bharat stage-II norms




4- wheelers manufactured as per Bharat stage-II,Bharat stage-III or subsequent norms



Diesel Vehicles:

Smoke density for all diesel driven vehicles should not exceed 65 Hartridge Smoke Units.

Effects on Human Health

The vehicular pollutants have damaging effects on both human health and ecology. Pollution Checking The human health effects of air pollution vary in the degree of severity, covering a range of minor effects to serious illness, as well as premature death in certain cases. These pollutants are believed to directly affect the respiratory and cardiovascular systems. In particular, high levels of Sulphur dioxide and Suspended Particulate Matter are associated with increased mortality, morbidity and impaired pulmonary function.




Effect on Human Health

Carbon Monoxide

Affects the cardio vascular system, exacerbating cardiovascular disease symptoms, particularly angina; may also particularly affect fetuses, sick, anemic and young children, affects nervous system impairing physical coordination, vision and judgments, creating nausea and headaches, reducing productivity and increasing personal discomfort.

Nitrogen Oxides

Increased susceptibility to infections, pulmonary diseases, impairment of lung function and eye, nose and throat irritations.

Sulphur Dioxide

Affect lung function adversely.

Particulate Matter and Respirable Particulate Matter (SPM and RPM)

Fine particulate matter may be toxic in itself or may carry toxic (including carcinogenic) trace substance, and can alter the immune system. Fine particulates penetrate deep into the respiratory system irritating lung tissue and causing long-term disorders.


Impairs liver and kidney, causes brain damage in children resulting in lower I.Q., hyperactivity and reduced ability to concentrate.


Both toxic and carcinogenic. Excessive incidence of leukemia (blood cancer) in high exposure areas.

Steps Taken by Delhi Govt. to reduce the Pollution in Delhi

Pollution Checking by Transport Department:

Mobile enforcement teams are being deployed on regular basis at road locations for prosecution of polluting vehicles and vehicles not having PUC Certificates.

Public Awareness:

Public awareness campaigns are conducted to raise social consciousness on the issue and educate motorists about the health hazards, statutory provisions and control measures viz. engine tuning and maintenance.

Catalytic Converters:

Since April 1995, only those 4-wheeled petrol driven vehicles are registered on first sale in Delhi , which are fitted with Catalytic Converters. 

Mass Rapid Transport System:

Mass Rapid Transport System is being constructed with the objective to place a non-polluting, efficient and affordable rail based mass rapid transit system for NCT of Delhi, duly integrated with other modes of transport.  

Phasing out of Old Commercial Vehicles:

With a view to reduce vehicular pollution in Delhi Hon’ble Supreme Court vide its orders in CWP No. 13029 of 1985 has banned the plying of following categories of vehicles in Delhi: -

More than 15 years old commercial/ transport vehicles.

Autos & Taxis driven on conventional fuels.

Diesel driven city buses.

Transport Department is ensuring the effective compliance of these directions through its enforcement teams.  The Govt. of Delhi has provided fiscal incentives by way of sales tax exemption and interest subsidy on loans for purchase of new replacement vehicles.

Tightening of mass emission standards for new vehicles:

Mass emission norms for new vehicles were introduced in the year 1991.  Subsequently, these norms have been tightened for new vehicles in all categories in 1996 and 2000.  At present, only vehicles (except 2 and 3 wheelers) complying with Bharat Stage III/Euro-III emission norms and 2 and 3 wheelers complying with Bharat Stage II/Euro-II emission norms are being registered in the Delhi .

 Improvement in Fuel Quality:

The quality of the fuel being supplied in Delhi has been significantly improved during recent years by way of: -

·         Leaded petrol has been completely phased out.

  • Introduction of Low Sulphur diesel w.e.f August 1997 reducing Sulphur content from 0.8% gm/litre to 0.25% gm/litre. The Sulphur content of diesel supplied to NCT Delhi has been further reduced to 0.05% w.e.f. March, 2001.
  • The quality of petrol being supplied to Delhi has been improved further by reduction of Sulphur content to 0.05% & Benzene Content to 1%.

       Ministry of Road Transport and Highways, Government of India has tightened the emission level of CO and introduced the measurement of HC emissions in petrol vehicles. In respect of Diesel vehicles, Oil temperature & RPM measurement has been included in the test procedure. In compliance with the Gazette notification all the    pollution   checking Centres have been directed to get their equipment upgraded/modified/replaced with the new 4-gas analyzer and wherever they have failed to do so their authorisation has been cancelled.                                                                                                                

Pollution Checking Centres in Delhi









Steps for Pollution Checking
  • Pollution checking fee would be charged against a receipt.
  • Vehicle would be checked as per the prescribed procedure.
  • Puc certificate would be issued if vehicle passes the emission standard otherwise rejection slip would be issued.