BS EN ISO 13849-1-2023 PDF

Full title and description

STB BS EN ISO 13849-1:2023 — Safety of machinery — Safety-related parts of control systems — Part 1: General principles for design. This document is the British (BS) and European (EN) adoption of the ISO 13849-1:2023 international standard that defines the methodology, requirements and guidance for the design and integration of safety‑related parts of control systems (SRP/CS) for machinery, including software aspects.

Abstract

This standard specifies a methodology and provides requirements, recommendations and guidance for the design and integration of safety‑related parts of control systems (SRP/CS) that perform safety functions for machinery. It applies to SRP/CS used in high‑demand and continuous‑mode operation and covers associated subsystems regardless of technology (electrical, hydraulic, pneumatic, mechanical). The standard does not cover low‑demand mode of operation (see IEC 61508), does not itself specify required PLr values for particular applications, and does not replace product/component‑specific standards. The 2023 edition adds updated guidance (including new annex content) to support software design and component data for reliability calculations.

General information

• Status: Published / Current.
• Publication date: ISO edition published April 2023 (ISO 13849-1:2023); adopted as BS EN ISO 13849-1 published 04 May 2023 (BSI national publication).
• Publisher: British Standards Institution (BSI) — national adoption of the ISO 13849-1:2023 International Standard (ISO).
• ICS / categories: 13.110 (Safety of machinery / functional safety).
• Edition / version: Edition 4 (2023) — ISO 13849-1:2023 (published as EN ISO and BS EN national adoption).
• Number of pages: ISO record: 152 pages (ISO edition); BS national publication typically paginates to ~170 pages (BSI).

Scope

ISO 13849-1:2023 defines principles for the specification, design, integration and validation of safety‑related parts of control systems (SRP/CS) that implement safety functions on machinery. It covers SRP/CS for high‑demand and continuous operation modes and their subsystems, addresses both hardware and software aspects of SRP/CS design, and provides methods to determine required and achieved performance (e.g., categories, Performance Levels (PL), MTTFd, diagnostics and common‑cause considerations). The standard excludes low‑demand mode of operation (see IEC 61508) and does not set application‑specific PLr values; product/component specific requirements may be found in other ISO/IEC standards or Type‑C standards.

Key topics and requirements

• Definition and delimitation of SRP/CS (safety‑related inputs to safety‑related outputs).
• Risk‑based specification of safety functions and allocation of required risk reduction to SRP/CS.
• Performance assessment: Categories (B, 1, 2, 3, 4), Performance Levels (PL a–e), MTTFd (mean time to dangerous failure), diagnostics coverage (DC), and PFHd concepts where applicable.
• Design principles for hardware and software of SRP/CS, including redundancy, fault‑tolerance and avoidance of common‑cause failures.
• Validation, verification and testing requirements for SRP/CS; documentation and safety‑requirements specification (annex updates in 2023 edition provide added guidance).
• Guidance on use of component reliability data and data libraries to support calculations (new annex material and alignment with tools such as SISTEMA/PAScal).

Typical use and users

Primary users are machine manufacturers, control‑system designers, functional safety engineers, system integrators, notified conformity assessment bodies, and health & safety professionals. The standard is used when designing or assessing SRP/CS, preparing technical documentation for CE/UKCA conformity, performing risk assessments that allocate control‑system risk reduction, and validating safety functions in industrial machinery and related equipment.

Related standards

Commonly used in conjunction with: ISO 12100 (general machine safety and risk assessment), IEC 62061 (functional safety of electrical/electronic/programmable control systems for machinery), IEC 61508 (functional safety of electrical/electronic/programmable electronic safety‑related systems), ISO/TR 22100‑4 (safety & security interactions), and national EN/IEC derivative standards. BS EN ISO 13849-2 (where applicable) and other Type‑C standards provide additional product‑specific requirements.

Keywords

Safety of machinery, SRP/CS, safety‑related control systems, Performance Level (PL), category, MTTFd, diagnostics, functional safety, risk reduction, validation, software safety.

FAQ

Q: What is this standard?

A: ISO 13849-1:2023 (published as BS EN ISO 13849-1:2023 in the UK) is an international standard giving general principles for the design, integration and validation of safety‑related parts of control systems for machinery. It replaces the 2015 edition and updates guidance for hardware and software safety design.

Q: What does it cover?

A: It covers methodology, requirements and recommendations for SRP/CS used in high‑demand and continuous operation modes, including allocation of required risk reduction, performance assessment (categories, PL, MTTFd, diagnostics), avoidance of common‑cause failures, and validation/documentation. It does not apply to low‑demand mode (IEC 61508 covers that domain) and does not itself set application‑specific PLr values.

Q: Who typically uses it?

A: Machine builders, control and safety system designers, functional safety engineers, integrators, conformity assessment bodies and safety assessors use this standard to design, verify and document safety‑related control systems and to demonstrate conformity with applicable machinery safety regulations.

Q: Is it current or superseded?

A: The 2023 edition (Edition 4) is the current published edition and supersedes ISO 13849-1:2015. National adoptions (e.g., BS EN ISO 13849-1:2023) were published in 2023 and give the standard its national presumption of conformity where harmonised.

Q: Is it part of a series?

A: Yes — ISO 13849 is a multi‑part series; Part 1 covers general principles for design (this document). Other related parts or companion documents and Type‑C standards address validation, application specifics and product/component requirements. It is also used alongside other functional safety standards such as IEC 62061 and IEC 61508 depending on application and demand mode.

Q: What are the key keywords?

A: Safety‑related parts of control systems (SRP/CS), Performance Level (PL), category, MTTFd, diagnostics, validation, machine safety, risk reduction, functional safety.