What is NEN-EN-ISO 13850?
NEN-EN-ISO 13850 is the international standard that sets requirements for the function of the emergency stop device on machines. The standard defines how an emergency stop should function, how it should be operated and the requirements the button itself must meet.
The standard applies to all machines where there is a risk that people or equipment could be harmed by unexpected or uncontrolled movements. The Machinery Directive requires compliance with this standard during design and CE marking.
🧠 What does NEN-EN-ISO 13850 govern?
- Purpose of the emergency stop
- The rapid and safe shutdown of hazardous motion
- Limiting harm to people, machines or surroundings
- Design and operation
- Round red push-button on a yellow background
- Latching mechanism: stays in the depressed position until reset
- Operated with one hand, without tools
- Functional requirements
- Operates independently of the normal stop function
- Interrupts the power supply or control signal via a safety relay or Safety PLC
- The machine must not restart automatically
🏭 Application in industrial automation
- Machines with moving parts: presses, robots, conveyors
- Panel building: control cabinets, HMI, local operator stations
- Mobile installations, units in the process industry
- Production lines with multiple operator stations
Every operating location must be equipped with an easily accessible and visible emergency stop.
🔍 Emergency stop in accordance with ISO 13850
| Requirement | Explanation |
|---|---|
| Colour and shape | Red + yellow, mushroom-shaped |
| Accessibility | Unobstructed, no risk to the user |
| Restart | Only after manual reset by an authorised person |
| Safety level | Must meet the required PL or SIL (where applicable) |
| Inspection and maintenance | Regular functional inspection required |
The emergency stop is not a preventive measure but a corrective last resort in the event of danger.
🔐 Safety considerations
- Always include in the safety circuit with a safety relay or Safety PLC
- Reset must only be possible from outside the danger zone
- Restart requires explicit user action – no auto-reset
- Mention in risk inventory and evaluation, work permits and training is mandatory
- Carry out regular visual inspection and functional testing
A poorly placed or non-functioning emergency stop will result in immediate failure during inspection or CE audit.
📌 In summary
NEN-EN-ISO 13850 specifies how an emergency stop must be designed, positioned and applied on machines. The standard ensures that emergency stops are reliable, react quickly and contribute to safe working environments.