What causes fire in CNG cars and how to remain safe?

CNG or Compressed Natural Gas has become one of the most preferred automobile fuels in India. The prime reasons for its wide acceptance are cost advantage, clean nature, and a high calorific value.

CNG is the cleanest of all fossil fuels. The current price in Delhi as on August 6, 2018 is Rs 40.61 per Kg, which is way less than the price of petrol and diesel. CNG also carries a high calorific value of 50,000 kJ/kg as compared to petrol which has calorific value of 45000 kJ/kg. Calorific value is the amount of energy produced by the complete combustion of a material or fuel. Thus, the surge in the number of CNG-run vehicles in India, primarily in metro cities, is no surprise.

But CNG-run vehicles have a great chance of catching fire if you are not careful. Here are a few reasons:

Lack of maintenance

This is one of the prime causes of fire in CNG cars. Cars should be checked at regular intervals. The old wires have a great chance of losing their insulation, leading to a short circuit .The pre-installed CNG kit has to be checked time to time.

Carelessness on owner's part

Certain activities like smoking in the car, carrying flammable materials, firing crackers near your car, prolonged use of heater can be risky. CNG has an ignition temperature of 540 degree Celsius, which is very much attainable.

Unauthorized CNG kits

Some car owners fit CNG kit in their petrol or diesel cars. To save money, people often get this done from roadside dealers and mechanics. However, substandard quality kits and improper fitting can cause leakage, resulting in fire.

Use of aftermarket accessories

Aftermarket is the secondary market concerned with the sale and installation of all automobile components. Such accessories are prone to damage and fire as their voltage and current ratings may not tune with those of original accessories and wiring of the car. Tampering of the Original Equipment Manufacturer (OEM) wiring for such accessories could lead to short circuit or spark.

Leakage of gas

There can be CNG leakage in your car due to many reasons like overfilling of the fuel tank, improper fitting and gradual leakage with time. The best solution to leakage is to detect it immediately and then get the problem fixed from an authorised service center. The leakage is easily detectable due to a foul smelling agent present in the CNG.  

Accidents /Crashes

There is a chance that a CNG vehicle may catch fire immediately after an accident. If not, the danger may still persist. A sudden strike or jerk, might cause the CNG kit's fittings to loosen up. If this goes unnoticed, it can lead to a fire.

How to remain safe?

Indraprastha Gas Limited, one of India's leading natural gas distribution companies, has stated the following preventive methods to reduce the chance of accidents in CNG run automobiles.Ensure that the CNG cylinder installed in the vehicle is within the periodic test life, which is three years.

• Never ask for refueling beyond the allowable maximum pressure of 200 Bars under any circumstances.
• Never install CNG kit/ cylinder in the vehicle from any un-authorized road-side conversion workshop/ outlet.
• Use only the approved brands, imported, seamless brand new CNG cylinders manufactured as per relevant standard.
• Get CNG cylinder test certificate from the CNG licensee/Retrofitter after conversion of vehicle to CNG.

Edited By Rahul Bhargave