European Standard · Machine Safety
ISO 12100 – Safety of Machinery: General Principles for Design and Risk Assessment
ISO 12100 is the foundational international standard for machinery safety, providing general principles for risk assessment and risk reduction in the design of machinery, forming the basis that underpins most machine-specific safety standards and the wider hierarchy of controls used in workplace PPE decisions.
1. Scope
ISO 12100 applies to the design process for all types of machinery, establishing a systematic methodology for identifying hazards, estimating and evaluating risks, and applying the hierarchy of risk reduction measures: inherently safe design, safeguarding and protective measures, and finally information for use (including PPE requirements).
2. Exclusions & Related Standards
- Sits above and informs the selection logic behind PPE standards throughout this site, since PPE is only the last line of defence in the hierarchy of controls this standard defines.
- Works alongside ISO 13849 for the design of safety-related control systems on machinery.
- Referenced by countless machine-specific type C safety standards that build on its general risk assessment framework.
3. Key Requirements & Marking
The standard requires a structured risk assessment process: hazard identification, risk estimation (considering severity and probability of harm), risk evaluation, and iterative risk reduction following the three-step method of inherently safe design, safeguarding/protective measures, and information for use, only relying on PPE as a residual control after other measures have been applied.
4. Testing Overview
As a design and risk assessment standard, ISO 12100 is not tested in the same way as a product standard; conformity is demonstrated through documented risk assessments, design records, and evidence that the three-step risk reduction method was properly applied during machine development.
5. Selection Guide
This standard is applied by machinery designers and manufacturers rather than selected by end users of PPE, but understanding its hierarchy of controls helps workplaces recognise that PPE should always be a residual measure, used after eliminating hazards through design and implementing engineering safeguards wherever possible.
6. Inspection, Care and Maintenance
- Risk assessments should be reviewed and updated whenever machinery, processes or the working environment change
- Maintain documentation of the risk assessment and risk reduction measures applied throughout the machine’s lifecycle
- Reassess residual risks periodically to confirm that protective measures and any required PPE remain adequate
- Ensure operators are trained on residual risks and the reasons for any PPE required as a result
7. Frequently Asked Questions
What is the hierarchy of controls described in ISO 12100?
It is a three-step method: first eliminate hazards through inherently safe design, then apply safeguarding and protective measures, and finally provide information for use, including any necessary PPE, for residual risks.
Does ISO 12100 replace the need for PPE?
No, but it establishes that PPE should be used to address only the residual risks remaining after design and engineering controls have been applied, not as a first line of defence.
Who uses ISO 12100?
Primarily machinery designers, manufacturers and engineers responsible for conducting risk assessments and designing safe equipment, though safety managers also reference it when evaluating workplace risk controls.
How does ISO 12100 relate to specific PPE standards like EN 397 or EN 388?
It provides the overarching risk assessment framework that identifies when PPE is necessary as a residual measure, while standards like EN 397 and EN 388 specify the actual performance requirements for that PPE.
Is ISO 12100 a certification you can get for a single product?
No, it is a risk assessment and design methodology standard applied throughout a machine’s design process, not a certification mark placed on individual PPE products.