To limit the probability that vehicle impact on, or mechanical damage to, the tank or ancillary equipment will lead to failure of the tank or equipment, which could lead to the escape of liquid, which could lead to the ignition of vapour from a nearby ignition source, which could lead to harm to persons.
To require additional safety measures to those of the basic requirements of Subsection 4.3.2. [as stated in Sentence 4.6.2.1.(1)].