Overview - ISO 13850:2006 (Emergency stop for machinery)
ISO 13850:2006, developed by ISO in collaboration with IEC technical committees, defines functional requirements and design principles for the emergency stop (E‑stop) function on machinery. It is energy‑independent and applies to most types of machines except where an E‑stop would not reduce risk, and excludes hand‑held portable and hand‑guided machines. The standard is a type‑B2 (generic safeguard) safety standard that complements guarding and other protective measures.
Key topics and technical requirements
- Emergency stop function: A single human action intended to avert or reduce hazards and stop hazardous machine motions.
- Availability and override: E‑stop must be operational at all times and override all other functions without impairing devices intended to release trapped persons.
- Stop categories: Two options based on risk assessment:
- Stop category 0 - Immediate removal of power or mechanical disconnection/declutching (with braking as required).
- Stop category 1 - Controlled stop with power available to achieve stopping, then power removal.
- Manual reset: After an E‑stop, the command effect must be sustained until manually reset. Resetting is only possible at the location where the E‑stop was initiated; reset must only permit restarting (not automatically restart).
- Emergency stop device design:
- Actuators must be easily actuated (e.g., mushroom pushbuttons, wires/ropes, bars, handles, in some cases foot‑pedals).
- Direct opening action with mechanical latching is required; electrical devices should conform to IEC 60947‑5‑5.
- Actuator colour RED on a YELLOW background where practicable; use IEC 60417‑5638 symbol when labelling.
- Environmental and reliability considerations: Components must tolerate expected operating conditions (vibration, dust, moisture, corrosion) and the frequency of operation; provisions for testing and preventing inadvertent actuation.
- Wires/ropes: Specific requirements for visibility, force/deflection, prevention of breakage, and inspection before reset.
Practical applications and who uses ISO 13850
- Machine designers and OEMs - to design compliant E‑stop controls and layouts.
- Safety engineers and risk assessors - to select stop category and validate E‑stop effectiveness during risk assessments.
- Control system integrators and electrical engineers - to implement emergency stop circuitry consistent with IEC 60204‑1 and IEC 60947‑5‑5.
- Plant managers and compliance officers - to define procedures, testing and reset practices and to ensure regulatory conformity.
Related standards
Keywords: ISO 13850, emergency stop, safety of machinery, emergency stop device, mechanical latching, manual reset, stop category, IEC 60204‑1, IEC 60947‑5‑5, machine safety.
