Report on standards for CNG vehicles and refilling stations
The current emission standards and safety measures for conversion of in-use vehicles to CNG are extremely lax. The emission standards only require the vehicles to meet the equivalent standards for diesel and petrol vehicles in force in the year of manufacture. This means that a pre-1996 vehicle after being converted to CNG would have to meet only the outdated emission standards of 1991. This regulation does not recognise that CNG technology is an inherently clean technology and can be designed to meet more stringent emissions standards to maximise emissions benefit.