Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · Safety standards

IEC 61508

Also known as: IEC 61508:2010, EN 61508

German: IEC 61508

IEC 61508 is the foundational international standard for the functional safety of electrical, electronic and programmable electronic (E/E/PE) safety-related systems. It defines a safety lifecycle and Safety Integrity Levels (SIL 1 to SIL 4) and serves as the basis for sector standards such as IEC 62061.

  • Standards
  • Technical documentation

In one sentence

IEC 61508 is the foundational functional safety standard for E/E/PE safety-related systems, with a safety lifecycle and SIL 1 to SIL 4.

Example

A manufacturer of safety PLCs develops its hardware and firmware to IEC 61508 and supplies a safety manual and SIL data that machine builders then use in their IEC 62061 or ISO 13849-1 calculations.

How it applies

  • Functional safety: The standard covers the whole safety lifecycle, from hazard and risk analysis through specification, realization, validation and operation to decommissioning. It distinguishes low-demand and high-demand or continuous modes of operation.
  • Structure: Seven parts; parts 1 to 3 contain the requirements for the overall system, hardware and software, the other parts definitions and guidance.
  • Machinery: Machine builders usually apply IEC 62061 or ISO 13849-1 instead. IEC 61508 matters for component manufacturers and for complex or novel technology not covered by the sector standards.
  • Technical documentation: Components developed to IEC 61508 come with a safety manual stating conditions of use, diagnostics and failure rates. These conditions must reach the integrator's design and the operating documentation.

IEC 61508 vs. IEC 62061

IEC 61508 is generic and reaches up to SIL 4. IEC 62061 is the machinery-sector standard derived from it, reaches up to SIL 3 and is written for safety-related control systems of machines; see Safety Integrity Level (SIL).

By knowledge.aitechdoc.world · Published September 25, 2026 · Last reviewed

Source: IEC 61508:2010, Functional safety of electrical/electronic/programmable electronic safety-related systems

Definitions follow the cited standards and specifications. Where a source is a copyrighted publication, such as an ISO, IEC or EN standard, the definition is a close paraphrase, not a verbatim quotation, so as not to infringe copyright. We recommend reading the original publication. The sections “How it applies” are editorial commentary by AI TechDoc Blog and are not part of any standard.

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