CNG, filled at the right pressure, in a proper certified cylinder, would NEVER go BOOM.
It is far far difficult to ignite NG, than other fuels, in an open atmosphere, i.e: leakage. It is lighter than the air, has very high dispersion rate. That makes it quite safe.
CNG blasts do not occur due to ignition. They are cursed by the usage of non standard or low pressure cylinders to fill CNG, mostly done by public transport drivers - or rarely due to the fact that people forget/ignore/never learnt their Gas laws.
In any case scenario, LPG, Petrol, Pakistani angenier's water kit, and of course molvis, are more of a BOOM hazard.
HOBC is not suitable for your car. Stick to the regular, and stop giving people in those 2hr CNG queues mini heartattacks