Machinery safety
EN ISO 12100
The Type-A standard that defines how machinery risk assessment and risk reduction are carried out. Every machinery Technical File rests on it.
Safety of machinery — General principles for design — Risk assessment and risk reduction
- Category
- Machinery safety
- Scope
- International
- Edition / refs
- ISO 12100:2010 (EN ISO 12100:2010)
MSA output
- Risk assessment (EN ISO 12100)
- Guard & access analysis
- PLr / SIL calculations
- CE Technical File
What is EN ISO 12100?
EN ISO 12100 sets out the terminology, principles and methodology for achieving safety in the design of machinery. As a Type-A (basic safety) standard it applies to all machinery, and it is harmonised under the Machinery Directive 2006/42/EC, so applying it gives a presumption of conformity with the Directive’s risk assessment principles.
It replaced EN ISO 12100-1, EN ISO 12100-2 and EN ISO 14121-1. Practical guidance on risk estimation methods is given in ISO/TR 14121-2. Type-B standards (for example EN ISO 13849-1 for control systems or EN ISO 14120 for guards) and machine-specific Type-C standards build on it.
Who it applies to
- Machine builders and OEMs designing machinery for the EU or UK market
- System integrators creating assemblies of machinery, who become the manufacturer of the assembly
- Anyone carrying out a substantial modification of existing machinery
- Safety engineers preparing the risk assessment for a Technical File
Key requirements
- 01
Determine the limits of the machinery
Intended use and reasonably foreseeable misuse, space, time and other limits, across every life-cycle phase from transport to decommissioning.
- 02
Identify hazards
Systematically identify hazards, hazardous situations and hazardous events for each task and life-cycle phase. Annex B lists typical hazards.
- 03
Estimate risk
For each hazard, combine the severity of harm with the probability of occurrence: exposure, occurrence of the hazardous event, and the possibility of avoiding or limiting harm.
- 04
Evaluate risk
Decide whether risk reduction is required and, after measures are applied, whether adequate risk reduction has been achieved.
- 05
Apply the three-step method
Inherently safe design measures first; then safeguarding and complementary protective measures; then information for use — in that order of priority.
- 06
Document the assessment
Record the machine, its limits, hazards, risk estimates, protective measures, residual risks and the standards applied.
Summary for orientation only. Always refer to the current official text of EN ISO 12100 and any applicable legislation.
MSA for EN ISO 12100
What MSA generates
Evidence produced from your engineering inputs, traceable end to end and exported to Word, PDF or Excel.
Risk assessment (EN ISO 12100)
A structured hazard register across life-cycle phases, with risk estimation, evaluation and a three-step risk reduction record.
Guard & access analysis
Guarding and access to danger zones, linked to the hazards each measure addresses.
PLr / SIL calculations
Where a measure relies on a control function, the required performance level or SIL is derived and carried forward.
CE Technical File
The risk assessment feeds the Technical File directly, traceable from hazard to measure to evidence. Exports to Word, PDF and Excel.
Frequently asked questions
Is EN ISO 12100 mandatory?
Harmonised standards are voluntary. However, the Machinery Directive and Regulation (EU) 2023/1230 both require a risk assessment, and applying EN ISO 12100 is the recognised way to demonstrate that it has been carried out in line with the essential requirements.
What is the difference between ISO 12100 and ISO 13849?
ISO 12100 is the overall method for risk assessment and risk reduction. ISO 13849-1 applies when a risk reduction measure depends on a safety-related control system; it specifies the performance level that control function must achieve and how to design for it.
Does ISO 12100 prescribe a risk matrix or scoring method?
No. It defines the elements of risk that must be considered but leaves the estimation method to the user. ISO/TR 14121-2 describes practical methods such as risk matrices, risk graphs and numerical scoring.
How does MSA keep the risk assessment up to date?
Hazards, measures and outputs are linked. When an engineering input changes, MSA regenerates all affected evidence instead of requiring manual edits across separate documents.
Generate EN ISO 12100 evidence from your own data
See how MSA turns your requirements, drawings and process data into certification-ready documents — fully offline.