Mechanical safety under the MDR is governed by Annex I Section 14 of Regulation (EU) 2017/745, which requires devices to be safe against physical hazards under normal and single-fault conditions. EN 60601-1:2006+A1+A12+A2+A13:2024 is the harmonised standard that provides the test methods — stability and tipping, moving parts and guards, drop and impact, enclosure integrity, sharp edges, and mass-related hazards. The MDR states the outcome. The standard supplies the yardstick. For a startup, mechanical safety is a design decision locked in before enclosure tooling, not a test-lab discovery.

By Tibor Zechmeister and Felix Lenhard. Last updated 10 April 2026.

TL;DR

  • Mechanical safety covers stability, tipping, moving parts, enclosure integrity, drop and impact resistance, sharp edges, and mass-related hazards — the physical ways a device can injure a patient, operator, or bystander.
  • The legal obligation lives in MDR Annex I Section 14 of Regulation (EU) 2017/745. EN 60601-1:2006+A1+A12+A2+A13:2024 is the harmonised standard that provides presumption of conformity for the mechanical safety aspects.
  • Stability testing typically requires a device to remain upright on a 10-degree slope and to survive defined push and lean forces without tipping. The exact angle and force depend on the device category and mass.
  • Enclosure integrity tests include impact with a defined energy, push force on walls, and protection against access to hazardous live parts — the standard's ingress protection and enclosure clauses work together.
  • Drop height for portable and hand-held equipment is specified by the standard and scales with the device mass and the intended use conditions. Hand-held devices face harsher drop profiles than trolley-mounted ones.
  • A mechanical safety failure at the test lab is almost always a design problem that existed at the CAD stage and would have been cheap to fix before tooling. It is never a test-lab problem.

Why mechanical safety matters as much as the electrical clauses

There is a story pattern Tibor has seen several times over the past decade of Notified Body work. A team arrives at a pre-compliance visit proud of the electrical design. Creepage distances clean. Leakage currents well inside limits. Power supply certified. Then the lab engineer puts the device on a 10-degree ramp and it falls over. The team is stunned. Nobody on the project had opened EN 60601-1 Clause 9 on mechanical hazards. They had treated 60601-1 as an electrical standard.

It is not. The full title of EN 60601-1:2006+A1+A12+A2+A13:2024 is "Medical electrical equipment — Part 1: General requirements for basic safety and essential performance," and the basic-safety half covers every physical way a device can harm a person. Electrical shock is one family. Mechanical injury is another. Thermal and radiation hazards are two more. Skipping any of them produces a non-conforming device, regardless of how clean the electrical report looks.

For startups, the painful part is the timing. Mechanical failures almost always trace back to decisions made before the first CAD freeze — centre of mass too high, enclosure walls too thin, a pinch point in the hinge, a sharp edge where an operator hand lands. By the time the test lab sees the failure, the fix is a new mould, not a firmware patch. The Subtract to Ship angle here is the same as everywhere else in electrical safety: read the standard before the design freezes, not after.

What mechanical safety covers under EN 60601-1

The mechanical hazards in EN 60601-1:2006+A1+A12+A2+A13:2024 are grouped into several families, each with its own test methods and acceptance criteria. A founder does not need to memorise the clause numbers, but does need to know the families and whether each one applies to the device.

Stability and mass-related hazards. Devices that can tip, fall, or shift during normal handling. Trolley-mounted systems, floor-standing devices, and portable equipment placed on tables are all in scope. The standard tests the device on a tilted surface and under applied lean and push forces.

Moving parts and entrapment. Rotating components, linear actuators, motorised arms, automatic doors, and any mechanism that can pinch, crush, or entrap a finger or a limb. The standard specifies minimum clearances, guard requirements, and energy limits for moving parts that a user might reach.

Enclosure integrity and impact resistance. The enclosure has to survive a defined impact energy and push force without exposing hazardous parts. A cracked enclosure that now allows finger access to a mains conductor is simultaneously a mechanical and an electrical failure.

Drop and shock. Portable and hand-held devices must survive foreseeable drops. The standard specifies drop heights based on device mass and intended use environment. After the drop, the device must still be basically safe.

Sharp edges and burrs. Operator-accessible surfaces cannot present unreasonable risk of cut or puncture. The test is partly mechanical inspection and partly tied to the risk management file for the specific hazards the device presents.

Mass-handling hazards. Devices above specified mass thresholds have additional requirements for handles, lifting points, and markings that limit how the device can be carried safely.

Each of these families maps to a clause set inside EN 60601-1:2006+A1+A12+A2+A13:2024 and each one feeds evidence against MDR Annex I Section 14. The mapping is not optional — the technical file has to show it.

Stability and tipping

Stability is the single mechanical test that most startups are surprised by. The principle is simple: a device that tips over during normal use can injure the patient or operator, and tipping is a foreseeable event. The standard forces the manufacturer to prove the device will not tip under the conditions of intended use.

The core test subjects the device to a tilted surface. The device, configured as it would be for transport or operation (whichever is worse), is placed on an inclined plane and the angle is increased. The device must remain upright — not tip — up to a specified angle. For typical mobile medical equipment the threshold is 10 degrees, though the exact angle depends on the device category, mass distribution, and whether the device has locked castors or fixed feet.

A related test applies lateral forces. A defined push or lean force is applied at the point most likely to cause tipping — typically a handle, an upper edge, or a point where an operator would naturally place a hand. The device must not tip under this force.

Design consequences of the stability tests are blunt. A tall, top-heavy trolley fails. A device with castors that spin freely when pushed fails. A laptop-on-a-pole design without a wide base fails. The fixes are always in the mechanical architecture: lower the centre of mass, widen the base, add locking castors, move the handle, reduce the height. Every one of those fixes is cheap on a CAD drawing and expensive on a tooled enclosure. This is why a half-day of stability review before tape-out pays for itself many times over.

Moving parts and guards

Any device with moving mechanical components must protect users and patients from contact hazards during normal and foreseeable misuse. The standard uses a test finger and a test probe to check whether an operator can reach moving parts through openings in the enclosure. If the probe reaches a moving part that could injure, the enclosure fails and needs a guard, an interlock, or a redesign.

Guards can be fixed (a cover that requires a tool to remove) or interlocked (a door that stops the mechanism when opened). Interlocks must themselves be reliable under single-fault conditions — a single failure of the interlock switch must not leave the hazardous motion active while the guard is open. This is where basic safety crosses into the risk management file, because the interlock architecture has to be justified against the hazard severity from EN ISO 14971:2019+A11:2021.

Energy limits also apply. Moving parts with low enough mass and speed may not require guards at all, because the kinetic energy is below the threshold at which injury becomes plausible. This is a legitimate Subtract to Ship move: if the analysis shows the moving part cannot cause harm, document that analysis and remove the guard. The precondition is that the analysis is written, defensible, and part of the risk file.

Drop and impact testing

Portable and hand-held devices must survive drops. The drop heights specified by EN 60601-1:2006+A1+A12+A2+A13:2024 depend on the device category, mass, and intended use environment. Hand-held devices face drop heights that reflect the reality of a dropped-from-the-hand event. Portable devices that are moved between rooms face different heights. Fixed installations face impact rather than drop tests.

After the drop, the device does not need to be fully functional — but it must remain basically safe. An enclosure crack that exposes mains wiring is a fail. A display that stops working but does not create any new hazard can be a pass, depending on whether the display is tied to essential performance. A battery compartment that pops open, exposing the cells, is a fail.

Impact tests apply to enclosure walls and panels. A defined impact energy is applied with a specified impactor at the most vulnerable point of the enclosure. The wall must not crack, deform, or separate in a way that creates a hazard. Thin plastic walls near mains sections fail this test often.

The defensive design moves are standard and well known: minimum wall thicknesses, reinforcing ribs near stress points, shock-absorbing features around screens and connectors, and battery compartments with secure latches. None of these are expensive at design time. All of them are expensive after tooling.

Enclosure integrity and access to hazardous parts

Enclosure integrity is where mechanical safety and electrical safety overlap directly. The enclosure has two mechanical jobs: resist physical damage, and prevent access to parts that would be hazardous if touched. Both jobs are tested.

The push-force test applies a defined static force to the enclosure walls. The enclosure must not deform in a way that permits the test finger to reach a hazardous part. The impact test, covered above, checks the dynamic version of the same question — does the enclosure still protect the user after a foreseeable impact?

Openings in the enclosure are tested with the standard's test probes. If a probe can reach a part that is hazardous — mains voltage, a moving mechanism, a high-temperature surface — the opening is too large or wrongly placed. The fix is either a smaller opening, a relocated component, or a barrier inside the enclosure.

For devices with ingress protection claims (IPXX ratings), the IP tests are performed on top of the 60601-1 enclosure tests. An IP-rated enclosure that passes the ingress tests can still fail the 60601-1 push-force or impact requirements, because the two test series check different things.

How mechanical safety maps to MDR Annex I

The mapping is anchored in Annex I Section 14 of Regulation (EU) 2017/745. Section 14 requires that devices be designed and manufactured so they can be used safely under normal conditions and in single-fault conditions, and so they remove or reduce the risks associated with construction and environment.

"Devices shall be designed and manufactured in such a way as to remove or reduce as far as possible: [...] the risks associated with the reasonably foreseeable external influences or environmental conditions, such as magnetic fields, external electrical and electromagnetic effects, electrostatic discharge, radiation associated with diagnostic or therapeutic procedures, pressure, humidity, temperature, variations in pressure and acceleration or radio signal interferences" — Regulation (EU) 2017/745, Annex I, Section 14.2.

Mechanical hazards are physical hazards, and every one of the test families above produces evidence against Section 14. The stability test addresses the foreseeable tipping condition. The moving-parts tests address entrapment and impact from mechanical motion. The drop test addresses foreseeable handling events. The enclosure tests address the requirement that construction does not expose users to unacceptable risk.

Devices that fall under Section 18 — active devices — inherit additional mechanical considerations where the energy source itself creates motion or mass hazards. Devices with programmable systems under Section 17 must also consider mechanical failures triggered by software behaviour (a motor commanded to move when a guard is open, for example). The mechanical evidence in the test report must be cross-referenced to the specific Annex I provisions it addresses. Missing cross-references are one of the most common Notified Body findings on mechanical sections of technical files.

Common mechanical safety failures

A short list of failures we have seen repeatedly, without attribution to any specific client. Each one is preventable at the CAD stage.

  • Tipping on the 10-degree ramp. Centre of mass too high, base too narrow. Fix: redesign the base or lower the heavy components.
  • Test finger reaches a mains terminal. A vent slot is too wide or a gap at an enclosure seam exposes interior parts. Fix: narrow the slots, add an internal barrier, or redesign the seam.
  • Enclosure cracks in the drop test near the display. Wall thickness insufficient around a stress concentration. Fix: reinforce the area or redesign the corner geometry.
  • Interlock defeated by a single failure. The interlock switch was specified as a commercial part with no redundancy and fails in a way that leaves the motion active. Fix: add redundancy or change the architecture to a fail-safe design.
  • Sharp burrs on a machined handle. A manufacturing finishing step was omitted. Fix: add the deburring step to the QMS production process.
  • Missing mass-handling markings. A device above the mass threshold lacks the required lifting-point markings and handles. Fix: label and add handles before the device ships.

Each of these has the same underlying shape: mechanical safety was not reviewed against the standard before the design froze.

The Subtract to Ship angle on mechanical safety

Mechanical safety is another domain where addition feels safest and is often the wrong instinct. A team worried about tipping tests adds mass to the base — which increases the handling mass threshold and triggers lifting-point markings. A team worried about enclosure cracks specifies thicker walls everywhere — which increases tooling cost and mass. A team worried about moving parts adds guards and interlocks everywhere — including on parts whose kinetic energy cannot cause harm.

The precise move is the same as in the basic-safety clauses of EN 60601-1:2006+A1+A12+A2+A13:2024. Identify the mechanical hazards the device actually presents, in its actual intended use, under its actual foreseeable misuse. Document the analysis in the risk management file. For each hazard that genuinely exists, design the minimum necessary control. For each hazard that the analysis shows does not exist, document the justification and remove the speculative control.

The obligation remains MDR Annex I Section 14. The standard is the efficient path to proving the obligation. Testing every possible mechanical scenario is not required. Testing the scenarios that correspond to real hazards of your specific device, with real acceptance criteria tied to real risk analysis, is.

Reality Check — Where do you stand?

  1. Have you read the mechanical clauses of EN 60601-1:2006+A1+A12+A2+A13:2024 — or at least the clauses relevant to your device type — before the first CAD freeze?
  2. Is your risk management file under EN ISO 14971:2019+A11:2021 open and feeding the mechanical hazard identification?
  3. Have you walked your design against stability, tipping, moving-parts reach, drop, impact, and enclosure integrity before the first mould was cut?
  4. For each mechanical test family, have you decided whether it applies to your device, and documented the justification either way?
  5. If your device has moving parts, have you defined which parts need guards or interlocks, and justified that decision against kinetic energy and hazard severity?
  6. Have you cross-referenced each planned mechanical test back to a specific provision in MDR Annex I Section 14?
  7. When a mechanical failure is found at the test lab, does your team have a change-control path that feeds the fix back into the risk file and the technical file — or does it stall the project?

Frequently Asked Questions

Is mechanical safety testing under EN 60601-1 mandatory for every medical electrical device? Not literally every device, but for devices in the scope of EN 60601-1:2006+A1+A12+A2+A13:2024, the mechanical clauses apply wherever the corresponding hazards are present. A small, fixed, tabletop device may not require drop testing. A trolley-mounted system requires stability testing. A device with moving parts requires guard and interlock verification. The risk management file and the standard's applicability analysis together decide which clauses apply. Skipping a clause whose hazards are present produces a non-conforming device.

What is the standard stability test angle? For typical mobile medical equipment the standard specifies a 10-degree angle on an inclined plane, with the device placed in the configuration most likely to cause tipping. The exact angle, along with the applied force conditions, depends on the device category, mass, and intended use. The current consolidated standard EN 60601-1:2006+A1+A12+A2+A13:2024 sets these values in the clauses on mechanical hazards and stability — the manufacturer confirms the exact figure for the specific device.

Does every portable device need a drop test? Yes, if it qualifies as portable or hand-held under the standard's definitions. The drop height and the number of drops depend on the device mass and the intended use conditions. After the drop, the device must remain basically safe — it does not have to remain fully functional unless the relevant function is defined as essential performance. Fixed-installation devices face impact tests rather than drop tests.

Is IP rating the same as enclosure integrity under 60601-1? No. IP rating addresses ingress of solid objects and liquids. EN 60601-1:2006+A1+A12+A2+A13:2024 enclosure integrity addresses mechanical strength, access to hazardous parts, push force, and impact. A device can hold a high IP rating and still fail the 60601-1 push-force test because the two test series check different properties. Both may apply to the same enclosure.

How do mechanical failures affect essential performance? A mechanical failure that leaves the device basically safe but disrupts a clinical function can be an essential performance failure, depending on how the manufacturer has defined essential performance. A display that goes blank after a drop is a fail if the display is part of essential performance and a pass if it is not. This is one more reason to define essential performance in writing before the test campaign begins.

Can we use third-party enclosures to skip mechanical testing? Only partly. A purchased enclosure with its own test history can reduce your testing burden for the enclosure itself, but the moment you modify it — adding cutouts, mounting holes, displays, connectors — the original test evidence is compromised for those modifications. And stability, moving-parts, and drop tests apply to the full assembled device, not to the bare enclosure, so they must be re-run on the finished product.

Sources

  1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Annex I Chapter II, Section 14 (construction of devices and interaction with their environment), Section 17 (electronic programmable systems), Section 18 (active devices and devices connected to them). Official Journal L 117, 5.5.2017.
  2. EN 60601-1:2006+A1+A12+A2+A13:2024 — Medical electrical equipment — Part 1: General requirements for basic safety and essential performance. Mechanical hazard clauses (stability, moving parts, enclosure integrity, drop and impact, mass handling).
  3. EN ISO 14971:2019+A11:2021 — Medical devices — Application of risk management to medical devices.

This post is part of the Electrical Safety & Systems Engineering Under MDR series in the Subtract to Ship: MDR blog. Authored by Felix Lenhard and Tibor Zechmeister. The MDR is the North Star. The mechanical clauses of EN 60601-1:2006+A1+A12+A2+A13:2024 are the tools that prove the construction requirements of Annex I Section 14 — useful, powerful, and only ever in service of the Regulation itself.