It is scary to think that there are as many as 950 compressed natural gas (CNG) taxis on the roads, after two recent incidents in which the tanks in the taxis exploded (CNG cabs must get safety check by tomorrow; May 24).

The explosions happened when cigarettes were lit.

According to Land Transport Authority's Taxi Vocational Licence rules, smoking by drivers is not allowed.

So why did the drivers light their cigarettes in the taxis?

Next, is the issue of safety of the CNG tanks.

Over time, gas tanks and their valves do wear out. There is also a possibility of tampering.

The authorities should ban all custom-installed CNG tanks and modifications to vehicles.

Only original CNG vehicles made by their respective manufacturers should be allowed on our roads.

Raymund Koh Joo Guan