Overview
EN ISO 14119:2025 (identical to ISO 14119:2024) - titled Safety of machinery - Interlocking devices associated with guards - Principles for design and selection - provides principles for the design, selection and application of interlocking devices associated with guards. It is published by CEN (adopted March 2025) and supersedes EN ISO 14119:2013. The standard is energy-source independent and gives guidance to minimize the possibility of defeat of interlocking devices in reasonably foreseeable situations.
Key topics and technical requirements
- Scope and purpose
- Principles for design and selection of interlocking devices and guidance to reduce deliberate or accidental defeat.
- Covers parts of guards that actuate interlocking devices and trapped key interlocking systems.
- Operating principles
- Interlocking with and without guard locking, actuator modes, cams and mechanical stops.
- Design and arrangement
- Requirements for fastening/arrangement of position switches, bolt locks, access locks and actuators.
- Rules for guard-locking devices (electromechanical, electromagnetic), locking force considerations and whole-body access.
- Supplementary releases & safety features
- Escape, auxiliary and emergency releases; requirements for interlock blocking and supplementary release selection.
- Selection and application
- System response time vs. access time, environmental considerations (e.g., dust effects), and criteria for trapped key systems.
- Human factors and defeat prevention
- Measures and system design approaches to reduce motivation and opportunities to defeat interlocks.
- Normative references
- Integrates with risk and control-system standards (see Related Standards).
Practical applications and users
Who uses EN ISO 14119:2025:
- Machine designers and OEMs selecting interlock hardware and guard actuation methods.
- Safety engineers and integrators implementing machine safeguarding and control-system interfaces.
- Compliance officers, notified bodies and assessors demonstrating conformity with the EU Machinery Directive (2006/42/EC) where the standard is cited.
- Maintenance personnel and safety managers specifying trapped key systems, lock types and emergency/escape release arrangements.
Typical applications:
- Selecting and positioning interlocks for access panels, hinged guards, removable covers.
- Designing trapped key interlocking in sequence control or lock-out procedures.
- Defining guard-locking solutions where personnel access and machine motion must be controlled.
- Ensuring safeguarding solutions align with functional safety requirements and risk reduction strategies.
Related standards
Key referenced standards for implementation and compliance:
Using EN ISO 14119:2025 helps organizations choose appropriate interlocking devices and document safe, defendable design choices for machine guarding and compliance.