What is ISO 12100?
ISO 12100 is the international foundation standard for risk assessment and risk reduction on machinery. The standard describes a structured method for identifying hazards, assessing risks and taking appropriate measures for the safety of people and installations.
In an OT context, ISO 12100 forms the basis for determining safety functions on machines, which are subsequently technically implemented via standards such as ISO 13849-1 or IEC 62061.
🧠 Purpose of ISO 12100
- Systematic risk assessment – From design through to commissioning
- Uniform process for designers and integrators
- Identification of hazards – Mechanical, electrical, thermal, functional
- Risk reduction in line with the 3-step model
- Foundation for CE marking under the Machinery Directive
🔍 The 3-step model of ISO 12100
- Inherent safety Design without risk (e.g. slowly rotating axes, limited force)
- Technical protective measures Safety components such as guards, light curtains, interlocks
- Use measures (instruction) Signage, manuals, warnings, training
This model is applied per identified risk, starting with elimination at the source.
🛠 Examples of hazard types in ISO 12100
| Hazard category | Example |
|---|---|
| Mechanical hazard | Crushing risk on moving parts or pressing mechanisms |
| Electrical hazard | Uninsulated connections in a control cabinet or motor |
| Thermal hazard | Burns from hot surfaces or steam |
| Radiation hazard | Welding radiation or IR sensors during detection |
| Functional hazard | Unexpected start due to a software fault in the PLC or HMI |
| Lack of ergonomics | Awkward posture during operation, manual tooling changes |
| . |
✅ Risk grading (S, F, P)
ISO 12100 uses three factors to assess risks:
| Factor | Meaning |
|---|---|
| S | Severity of possible injury |
| F | Frequency and duration of exposure |
| P | Possibility of avoiding or limiting the hazard |
This assessment provides the input for the PL calculation in ISO 13849-1 or SIL in IEC 62061.
🔁 ISO 12100 and other standards
| Standard | Relation to ISO 12100 |
|---|---|
| ISO 13849-1 | Technical realisation of safety functions via Performance Level (PL) |
| IEC 62061 | Alternative via Safety Integrity Level (SIL) |
| Machinery Directive | ISO 12100 is a harmonised standard under this EU directive |
| IEC 60204-1 | Safety of electrical equipment |
| ISO 14119 | Safety switches and interlocks |
📌 In summary
ISO 12100 is the foundation standard for identifying and managing risks on machinery. The risk assessment process is essential for CE marking, safety culture and the correct application of technical standards in OT environments.