What is IEC 61508?

IEC 61508 is the international standard for electrical, electronic and programmable electronic safety related systems. It sets out the requirements for ensuring that systems are designed, implemented, operated and maintained to provide the required safety integrity level (SIL). Four SILs are defined according to the risks involved in the system application, with SIL4 being applied for the highest risks. The standard specifies a process that can be followed by all links in the supply chain so that information about the system can be communicated using common terminology and system parameters.

Other standards are being produced for the application of the 61508 approach to particular sectors. IEC 61511 relating to the process industries has recently been published.

Basic information on this standard can be found on the IEE's Professional Network dedicated to Functional Safety.