Summary
In short
- ISO 12100 requires assessment across the whole machine lifecycle and all foreseeable tasks, including setting, cleaning, fault finding and maintenance, not only normal production.
- Machine guarding remains among the most frequently cited OSHA standards, and citations concentrate in the tasks where guards are opened, bypassed or reached past.
- EU Machinery Regulation 2023/1230 applies from 20 January 2027, replacing the Machinery Directive. There is no overlap period: machinery placed on the market before that date stays under the Directive.
- The Regulation defines substantial modification at Article 3(16). Anyone who modifies a machine in a way that creates a new hazard or increases existing risk can become the manufacturer for that modification, with the conformity obligations and liability that follow.
- That reaches operators, not only OEMs. Retrofitting an AI vision system, adding a robot or reconfiguring a line can trigger it.
- Cleaning is servicing under OSHA 1910.147(b), so sanitation access is both a guarding question and an energy control question.
What it is
What it is
What is a machine risk assessment?
A systematic assessment of the hazards a machine presents across every mode of operation and every task performed on it, leading to risk reduction through inherently safe design, safeguarding, and information for use. ISO 12100 provides the methodology and is the reference standard internationally.
Why assess by task rather than by machine?
Because guarding is designed around production mode, and the exposure lives in the other modes. Setting, clearing jams, adjusting, cleaning, sampling and maintaining all require access the guard exists to prevent. Almost every serious machinery injury occurs during one of these, and a machine-level assessment tends not to describe them.
When to use it
When to use it, and when not to
This assessment covers the machine and the tasks performed on it. Adjacent records handle the controls it specifies.
Use it for
- New machinery before first use, including secondhand and relocated equipment
- Existing machinery where no task-based assessment exists
- After any modification, retrofit or reconfiguration of the machine or its guarding
- When a new task is introduced, including changes to cleaning or sampling method
- Following an incident or near miss involving access to a hazardous part
Not for
- The machine-specific energy control procedure, which specifies isolation points and sequence and is a separate document
- Safety function validation, which tests interlocks and control system performance against their designed level
- Pre-use and periodic equipment inspection, which checks condition rather than assessing design
- The CE or UKCA technical file, which is the manufacturer's conformity documentation
- General workplace risk assessment, which will not address point of operation hazards adequately
Standards
What it is built against
Machine safety combines a design-side conformity regime with an employer-side duty to assess and control, and the two meet at modification.
| Clause | Requirement | Where it lands |
|---|---|---|
| ISO 12100 | Risk assessment and risk reduction: hazard identification across the lifecycle, estimation, evaluation and the three-step method | Lifecycle tasks |
| ISO 12100 cl.5.3 | Determination of limits including use limits, space limits, time limits and foreseeable misuse | Header |
| ISO 13849 / IEC 62061 | Performance level or safety integrity level for safety-related control system parts | Result |
| OSHA 1910.212 | Machine guarding at the point of operation, nip points, rotating parts and flying chips | Result |
| OSHA 1910.147(b) | Cleaning named within servicing and maintenance, bringing sanitation within energy control | Sanitation specific |
| EU 2023/1230 | Machinery Regulation applying from 20 January 2027, including substantial modification at Article 3(16) | Header |
| PUWER 1998 regs 11-19 | Dangerous parts guarded, controls, isolation, stability, lighting and markings | Result |
| CSA Z432 | Canadian safeguarding of machinery standard, aligned with the ISO approach | Whole record |
What it does not cover
- The machine-specific energy control procedure, which lists isolation points and the application sequence.
- Safety function validation, which tests interlocks, light curtains and safety control systems against their designed performance level.
- The technical file and declaration of conformity, which are conformity documents held by whoever placed the machine on the market.
- Pre-use and periodic inspection, which examines condition rather than assessing design adequacy.
- Operator training records, which evidence competence for the tasks the assessment describes.
Filling it in
Filling it in well
The method is settled. What separates a useful assessment from a filed one is the task list and the honesty about access.
Production, setting, changeover, clearing jams, adjusting, sampling, cleaning, lubricating, fault finding, maintenance, and returning to service. For each, record what access is required and how often it happens. A jam clearance performed forty times a shift is a different exposure from an annual overhaul, and both belong in the assessment.
The design intent is that the guard stays closed. The task requires reaching a specific point. Where those conflict, the assessment should say so rather than restating the procedure, because that conflict is where the injuries occur and it is the finding that drives redesign.
In food operations cleaning is a major access activity, frequently performed at night by agency crews, and it is named within servicing under 1910.147(b). The assessment should cover cleaning access explicitly: what must be opened, what must be isolated, what stored energy exists, and whether guards are correctly refitted before production resumes.
With the Machinery Regulation applying from January 2027, the question of whether a modification creates a new hazard or increases risk carries conformity consequences. Assess it before the retrofit, when the answer can change the design, rather than afterwards when it changes who is liable.
Audit findings
Common audit findings
Findings here concentrate on the modes that were never assessed.
| Finding | Clause | What fixes it |
|---|---|---|
| Assessment covers production mode only. | ISO 12100 cl.5.4 | Enumerate all lifecycle tasks; the injuries occur in the other modes. |
| Jam clearance, sampling or adjustment not described despite occurring frequently. | ISO 12100 cl.5.3 | Record frequency and access required; high-frequency short tasks carry the exposure. |
| Cleaning access not assessed, or treated as outside servicing. | 1910.147(b) | Cleaning is servicing; assess access and apply energy control. |
| Guard reinstatement after maintenance not verified. | PUWER reg.11 | Verify before restart; incorrectly refitted guards cause subsequent injury. |
| Safety functions specified with no performance level determined. | ISO 13849 | Determine required performance level and validate the implementation against it. |
| Modification made with no assessment of whether it is substantial. | EU 2023/1230 art.3(16) | Assess before the work; the answer determines who holds manufacturer obligations. |
| Foreseeable misuse not considered. | ISO 12100 cl.5.3 | Include what people actually do under pressure, not only intended use. |
| Secondhand or relocated machinery in use with no assessment. | PUWER reg.4 | Assess before first use; the previous site's assessment describes a different installation. |
| Assessment not revisited after a layout or line integration change. | ISO 12100 | Integration creates interface hazards that neither machine's assessment covers. |
| Control decision recorded without applying the three-step method. | ISO 12100 cl.6 | Record why inherently safe design and safeguarding were rejected before relying on information for use. |
Worked case
Case in point: the retrofit that changed who the manufacturer was
A producer added an AI vision inspection unit to an existing packing line, integrating it between two machines that had been CE marked separately by different suppliers. The integrator was a third party. The unit worked, throughput improved, and nobody raised a conformity question because the machines were existing equipment already on the market.
Under the Machinery Regulation applying from 20 January 2027, substantial modification is defined in the Regulation, and a physical or digital change not foreseen by the original manufacturer that creates a new hazard or increases existing risk makes the modifier the manufacturer for that machinery. Integration of separate machines into a line, and the addition of software performing a function that affects safety, are precisely the circumstances the definition addresses.
The practical consequence is not a fine in the first instance. It is that conformity assessment, the technical file, the declaration and the liability for that part of the line move to whoever made the change, frequently the operator rather than any supplier.
Definitions
Definitions and key terms
- Three-step method
- The ISO 12100 sequence: inherently safe design, then safeguarding and complementary protective measures, then information for use.
- Substantial modification
- Defined in EU Machinery Regulation Article 3(16). A change not foreseen by the manufacturer creating a new hazard or increasing risk.
- Foreseeable misuse
- Use of the machine in a way not intended but reasonably predictable, which the assessment must consider.
- Performance level
- The ISO 13849 measure of a safety-related control function's ability to perform under foreseeable conditions.
- Point of operation
- The area where the machine performs work on the material, and where guarding failures produce the most severe injuries.
- Lifecycle tasks
- All activities across transport, assembly, commissioning, use, setting, cleaning, maintenance, decommissioning and disposal.
- Complementary protective measure
- Emergency stop, means of escape and rescue, and provision for safe isolation, applied alongside safeguarding.
- Incomplete machinery
- An assembly that is almost machinery but cannot perform a specific application on its own, with its own conformity route.
FAQ
Frequently asked questions
Why do machinery injuries happen in non-production modes?+
Because guarding is designed around production, and setting, clearing, adjusting, sampling and cleaning all require access the guard exists to prevent. Those tasks are frequent, short, and feel disproportionate to a full isolation, so they get done with the guard open or bypassed. If most of your machine incidents occur outside production mode, the assessment is describing the wrong thing.
What changes with the EU Machinery Regulation?+
It applies from 20 January 2027, replacing the Machinery Directive, and applies directly in all member states without national transposition. It expands scope to autonomous mobile machinery, AI-based safety functions and software performing safety functions, adds cybersecurity requirements, permits digital instructions by default, and defines substantial modification in the Regulation itself. Machinery placed on the market before that date remains under the Directive with no recertification required.
Can modifying a machine make us the manufacturer?+
Yes, where the modification is substantial. A physical or digital change not foreseen by the original manufacturer that creates a new hazard or materially increases existing risk transfers manufacturer obligations for that machinery to whoever made the change. Retrofitting a vision system, integrating a cobot, or combining machines into a line are the common triggers, and operators frequently do all three without raising the question.
Does the assessment cover cleaning?+
It should, prominently. Cleaning is named within servicing and maintenance at 29 CFR 1910.147(b), and in food operations it is a major access activity performed at night, often by agency crews. Assess what must be opened, what must be isolated, what stored energy exists, and whether guards are verified refitted before production resumes.
Do we need to assess secondhand machinery?+
Yes, before first use. The previous site's assessment described a different installation, a different task set and different surrounding equipment. Relocation also frequently changes access, sightlines and the interfaces with adjacent machines, none of which the original assessment covers.
The agents
What the agents do with it
The assessment is a task list and a set of control decisions. What fails is the mode nobody enumerated and the retrofit nobody assessed.
Holds the assessment by task rather than by machine, and links each control decision to the guarding, procedure or training that implements it.
Connects the assessment to the asset, the energy control procedure and maintenance history, and flags guard removal for reinstatement verification.
Raises the substantial modification question inside management of change, before a retrofit rather than after it.
Covers sanitation access in food areas, where cleaning is both a machinery access mode and a hygiene requirement.
This template lives in KnowSafe — safety and compliance. Incidents, hazards, permits, inspections and the critical controls behind them.
Meet KnowSafe→Sources
Sources
- ISO 12100:2010, safety of machinery, general principles for design, risk assessment and risk reduction
- Regulation (EU) 2023/1230 on machinery, applying from 20 January 2027
- 29 CFR 1910.212 and 1910.147, machine guarding and control of hazardous energy, OSHA
- ISO 13849-1 and IEC 62061, safety-related parts of control systems
- Provision and Use of Work Equipment Regulations 1998, regulations 11 to 19 (GB)