For safety considerations, all motor vehicles are required to comply with vehicle construction and safety requirements before they can be registered for use on the roads.

The conversion of petrol-driven vehicles to bi-fuel (petrol-CNG) vehicles is allowed so long as the CNG components used comply with safety standards, such as UNECE Regulation 110 or ISO standards. These components need to be installed in accordance with Technical Reference 11 for CNG vehicle component and installation published by Spring Singapore in 2003.

For the safety of vehicle occupants and other road users, stringent tests according to these regulatory standards need to be carried out on the components before they are certified safe for use on vehicles in Singapore. For example, CNG tanks are subjected to impact tests, bonfire tests, as well as bullet penetration tests to ensure they do not rupture or explode.

These standards also require provision for the CNG to be vented outside the vehicle in the event of any gas leakage. CNG, being lighter than air, will disperse quickly and not linger around the vehicle when discharged.

Currently, we have approved seven CNG system suppliers which have been authorised by the CNG system manufacturers to distribute and install CNG kits. These suppliers have the necessary facilities to install CNG systems in vehicles in accordance with the CNG system manufacturer's recommendations and the Technical References for CNG system components, installation and workshop facilities. As part of the approval process, they have to prove that technical staff responsible for installation of the CNG kit have been trained by the CNG kit manufacturers and are qualified to carry out the installation. As an added safety measure, we require the mounting of CNG tanks to be certified by a professional engineer to ensure they will not dislodge at impact forces up to 20 times gravitational acceleration.

Geoffrey Lim
Deputy Director, Media Relations
Land Transport Authority