Which IEC standard relates to Safety Integrity Levels (SIL)?

The standard related to Safety Integrity Levels (SIL) is IEC 61508. This standard provides a framework for determining the necessary safety integrity levels required for safety-related systems, particularly in the context of industrial automation and control systems. It defines the requirements for ensuring a sufficient level of safety in the design and deployment of these systems, including the systematic approach to risk assessment, safety lifecycle management, and ensuring the reliability and performance of these safety systems.

IEC 61508 is critical in supporting industries that require strict safety measures and helps organizations establish processes that contribute to the safe functioning of their operations. The concept of SIL is pivotal within this standard, as it helps organizations categorize safety systems based on their capability to perform under defined conditions, effectively supporting risk management.

The other standards mentioned focus on different aspects: IEC 62061 is specifically related to functional safety of safety-related control systems in machinery, whereas IEC 62351 deals with the security of power system control systems. IEC 60870 pertains to telecontrol protocols for monitoring and control in electrical engineering, which does not directly address Safety Integrity Levels.