Overview
ISO 14118:2017 - Safety of machinery - Prevention of unexpected start-up defines engineered measures to prevent unintended or unexpected machine start-up so people can safely enter and work in danger zones. The standard applies to start-up from all energy sources (electrical, hydraulic, pneumatic, stored energy such as gravity or springs, and external influences like wind). ISO 14118:2017 is a type‑B (generic) standard: it identifies available means but does not prescribe performance levels (PLs) or safety integrity levels (SILs) for safety‑related control systems, nor the exact measures for specific machines - those are determined by risk assessment or by a type‑C standard.
Key topics and requirements
- Risk assessment: Conduct per ISO 12100 to identify necessary prevention measures for unexpected start‑up.
- Isolation and energy dissipation: Provide manual devices for isolating power supplies, locking/securing isolating units, and dissipating or restraining stored energy.
- Verification: Include procedures (e.g., measurement, safe working procedures) to verify isolation and energy dissipation have been achieved.
- Design for frequent interventions: When manual isolation is impractical for frequent short interventions, provide additional controlled automatic functions.
- Prevention of unintended start commands: Address causes such as control failures, unintended actuator activation, restoration of power, and external influences.
- Signalling and delayed start: Use warnings and delayed‑start features where appropriate to reduce risk during re‑energization.
- Documentation: Describe procedures, means, energy sources and tasks in machine instructions and on‑machine warnings.
- Scope limitation: ISO 14118:2017 explicitly does not specify PLs/SILs; refer to ISO 13849‑1 or IEC 62061 for control system functional safety.
Applications and users
ISO 14118:2017 is intended for:
- Machine manufacturers designing built‑in measures to prevent unexpected start‑up.
- Health & safety bodies and market surveillance authorities.
- Maintenance and service providers who perform interventions in danger zones.
- Machine users/employers who need documented isolation and verification procedures.
Practical applications include maintenance isolation procedures, design choices for energy restraint/dissipation, and integration of warning/delayed‑start features to protect personnel.
Related standards
- ISO 12100 (risk assessment and risk reduction)
- ISO 13849‑1 (safety‑related parts of control systems)
- IEC 62061 (functional safety of electrical/programmable control systems)
Using ISO 14118:2017 helps reduce hazardous unexpected start‑up events by guiding designers and users on isolation, stored‑energy control, verification, and documentation - essential elements for safe machinery operation and maintenance.