EN 81-50 is the European standard that sets out the design rules, calculations, examinations and tests of lift components referred to by other lift standards. It is the companion document to EN 81-20: where EN 81-20 defines what a completed installation must achieve, EN 81-50 defines how an individual component is calculated and type-tested. Clause 5 contains the type-test procedures for the safety components listed in the EU Lifts Directive, including landing door locking devices, safety gears, overspeed governors, buffers, unintended car movement protection means and rupture valves. The current edition is EN 81-50:2020. An EU type-examination certificate for a safety component is issued against these procedures, which is why the two standards are always quoted together.