ISO 14118:2017 specifies requirements for designed-in means aimed at preventing unexpected machine start-up (see 3.2) to allow safe human interventions in danger zones (see Annex A). ISO 14118:2017 applies to unexpected start-up from all types of energy source, i.e.: - power supply, e.g. electrical, hydraulic, pneumatic; - stored energy due to, e.g. gravity, compressed springs; - external influences, e.g. from wind. ISO 14118:2017 does not specify performance levels or safety integrity levels for safety-related parts of control systems. While available means to prevent unexpected start-up are identified, this document does not specify the means for the prevention of unexpected machine start-up for specific machines. NOTE A type-C standard can define the required means for the prevention of harm arising from unexpected start-up. Otherwise, the requirements for a specific machine need to be determined by risk assessment outside the scope of this document.