European norm 13160

The standard EN 13160 shows five different classes (technical methods) of leak detection systems to be used on tanks and pipes.

The classes are listed in order of protection for the level of safety or environmental protection required.

By this classification each European country can choose, which class or classes shall be used or may be used or, which class or classes shall be excluded from use.

The standard is  mandated in Europe and valid since the  year 2003.

Situation in Europe
Nearly all European countries require since many years double walled tanks and more and more class I leak detection systems, as these systems realizes the highest protection level for the environment.
Class II systems are under criticism since years, as the leak detection liquid is defined as a water polluting liquid itself.
Some countries already prohibited to install new class II systems, as there are for example Switzerland, Austria, Germany and Italy.