ISO 13849

ISO 13849 is the international standard for the safety-related parts of machinery control systems. It uses a Performance Level (PL) classification rather than the SIL ratings of IEC 62061, and applies to electrical, electronic, hydraulic, pneumatic, and mechanical safety functions on industrial machinery.

Last updated: April 2026

Key Facts

Full name: ISO 13849-1 (Design) and ISO 13849-2 (Validation)
Title: Safety of machinery — Safety-related parts of control systems
Latest revision: ISO 13849-1:2023
Sister standard: IEC 62061 (machinery, electrical/electronic/programmable only)
Classification: Performance Level (PL): a, b, c, d, e (e is highest)
Demand mode: High demand or continuous demand
Architecture categories: B, 1, 2, 3, 4
Calculation inputs: Architecture, MTTFd, DCavg, common cause failure
Software tool: IFA SISTEMA (free, widely used)
Typical course length: 2 to 3 days
Common audience: Machine builders, control engineers, integrators, machinery safety assessors
Recognised schemes: TUV Rheinland, TUV SUD

What is ISO 13849?

ISO 13849 covers the design and validation of safety functions on machinery control systems. Unlike IEC 62061, which is restricted to electrical, electronic, and programmable systems, ISO 13849 covers a broader range of technologies including pneumatic, hydraulic, and mechanical safety functions. The standard introduces Performance Level (PL) as its integrity measure, ranging from PL a (lowest) to PL e (highest). PL is calculated from the architecture (Category B, 1, 2, 3, or 4), MTTFd (mean time to dangerous failure), and DCavg (average diagnostic coverage). According to a 2013 industry survey, more than 89% of machine builders use ISO 13849 as their primary functional safety standard.

ISO 13849 vs IEC 62061

Aspect	ISO 13849	IEC 62061
Scope	Electrical, electronic, programmable, hydraulic, pneumatic, mechanical	Electrical, electronic, programmable only
Integrity measure	Performance Level (PL a to e)	SIL (SIL 1 to 3)
Demand mode	High or continuous	Low or high demand
Typical use	Most machinery	Complex programmable safety control
Adoption	Most widely adopted in machinery	Used alongside ISO 13849 in complex systems

How ISO 13849 Relates to Other Standards

ISO 13849 is one of two functional safety standards available for machinery; IEC 62061 is the other. Both reference IEC 61508 as the parent functional safety standard. ISO 12100 (general machinery risk assessment) typically precedes ISO 13849 work — risk assessment under ISO 12100 identifies the safety functions, and ISO 13849 designs them. The European Machinery Directive cites both ISO 13849 and IEC 62061 as means of demonstrating compliance for safety-related control systems.

How Machinery Safety Training Providers Deliver ISO 13849 Training

The standard format is 2 to 3 days of instructor-led training covering the architecture categories, PL determination, and the IFA SISTEMA software tool used to calculate PL achieved. Many providers bundle ISO 13849 with IEC 62061 in a 4 to 5 day machinery safety course, since both standards apply in complex projects. Recognised scheme certifications (TUV Rheinland, TUV SUD) are the dominant credentials. An LMS supporting ISO 13849 training needs cohort scheduling for certification cycles, integration with SISTEMA exercise files, identity verification at exam, verifiable certificates, and audit-ready records.

Common Questions

Can I use ISO 13849 instead of IEC 62061?

Yes, for many machinery applications. ISO 13849 is more widely adopted because it covers a broader range of technologies. IEC 62061 is preferred for complex programmable safety control systems where SIL allocation is more familiar to the design team.

How is PL different from SIL?

PL is calculated from architecture, MTTFd, and DCavg. SIL is calculated from probability of failure on demand. The two ranges are conceptually similar (PL a to e roughly maps to SIL 1 to 3) but use different metrics. They are not directly interchangeable.

What is SISTEMA?

SISTEMA is a free software tool from IFA (the German Institute for Occupational Safety and Health) that helps calculate PL according to ISO 13849. It is the de facto standard tool for machinery safety practitioners working under ISO 13849.

Does ISO 13849 require independent assessment?

For most categories of safety function, no formal independent assessment is required. The manufacturer typically validates internally. For higher-risk applications or specific certification schemes, independent assessment may be required.

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