The new prEN ISO 13849-2

The revised title alone highlights the fundamental change in the standard:

• 2012: Safety of machinery – Safety-related parts of control systems – Part 2: Validation
• Draft 2026: Safety of machinery – Safety-related parts of control systems – Part 2: Application of design and validation principles

Part 2 is therefore no longer merely the ‘document for the final inspection’, but is intended as a practical guide that actively supports the safe design of safety-related control systems. Validation is no longer viewed in isolation, but as a logical consequence of a design implemented in accordance with the standard.

In practice, this means that safety concepts must be thought through at an earlier stage and technically sound, and cannot be checked only at the end of a project.
 

2. Relocation of validation content to EN ISO 13849-1

One of the most significant structural changes is evident in the structure of the standard: Part 2 of the 2012 version contained Chapters 4 to 12 with detailed requirements for

• validation by analysis,
• validation by testing, assessment of safety functions, performance levels and categories,
• as well as environmental, maintenance and documentation requirements.

These requirements from the 2012 edition have been fully incorporated into EN ISO 13849-1:2023. The forthcoming Part 2 now focuses consistently on principles, proven technical approaches and their application. The result is a clearer division of roles: Part 1 covers requirements, methods and validation, whereas Part 2 provides practical guidelines for safe design and technical implementation.

3. Focus on safety principles and proven components

The centrepiece of the new draft is Section 4, which systematically describes:

• fundamental and proven safety principles,
• requirements for so-called proven components, and
• conditions under which faults or the consequences of faults may be ruled out.

Table 2, in conjunction with the tables in the annexes, is particularly relevant in practice. It summarises typical technical approaches for fulfilling these principles. This means that knowledge which was previously largely based on experience is now, for the first time, presented in a structured manner within the standard.

At the same time, however, the responsibility placed on designers and project managers increases. The selection of proven components and the justification for excluding faults must be technically sound, verifiable and documentable.

4. Significant enhancement of Annexes A to D

The existing annexes for mechanical systems (Annex A), pneumatic systems (Annex B), hydraulic systems (Annex C) and electrical systems (Annex D) remain in place and have been significantly expanded in terms of content in the 2026 draft.

New additions include, amongst others:

• clearer guidelines on proven components in Tables A.3, B.3, C.3 and D.3,
• a new Table D.22 on the handling of transmission errors,
• a new Section D.3 on the consideration of so-called soft errors.

The previous Annex E has been omitted entirely, as its contents are now covered in Part 1.

The annexes are thus evolving from purely reference works into active tools for planning, assessment and justification.

5. Alignment with the new Machinery Regulation (EU) 2023/1230

Another significant difference lies in the regulatory context. The draft prEN ISO 13849-2:2026 continues to include Annex ZA, which explains the relationship with the Machinery Directive 2006/42/EC. A new addition is Annex ZBB, which outlines the alignment with the new Machinery Regulation (EU) 2023/1230.

This makes it clear that the standard is specifically geared towards the future legal framework, which will become binding from 20 January 2027. This provides companies with early guidance and planning certainty when implementing future conformity requirements.

Conclusion

The draft prEN ISO 13849-2:2026 marks a fundamental shift in the understanding of Part 2 of the series of standards. It moves from being a purely validation-based standard to a practice-oriented guide that actively supports the safe design of safety-related control systems.

For manufacturers and integrators, this means:

• greater integration of design, risk assessment and validation,
• greater emphasis on safety principles and proven technical solutions,
• greater transparency, but also higher technical requirements for implementation.

Those who address the changes at an early stage will create a solid foundation for future machine concepts and ensure that functional safety is implemented not only in compliance with standards, but also in a sustainable and traceable manner.

Posted on: 2026-05-04