Classification of Medical Devices: Understand Each Risk Level

The classification of medical devices is an essential step in the regulatory process. It determines the level of risk associated with the product and defines the technical and clinical requirements necessary for its approval and marketing.

Below, I explain the main risk classes used by regulatory agencies.

1. Classification according to ANVISA (Brazil)

ANVISA classifies medical devices into four risk classes, based on the criteria of Regulation RDC No. 751/2022:

•Class I - Low Risk:

Simple devices, for non-invasive use, with transient contact with the body.

Examples: dressings, digital thermometers.

• Class II - Medium Risk:

Devices a little more complex, but still considered of moderate risk.

Examples: syringes, surgical gloves, dental instruments.

•Class III - High Risk:

Invasive, implantable or drug-releasing products.

Examples: orthopaedic prostheses, vital signs monitors.

• Class IV - Very High Risk:

Critical devices, usually implantable or that support life.

Examples: pacemakers, implantable defibrillators, heart valves.

2. Classification according to the FDA (United States)

In the US, the FDA uses three main classes based on the risk of the device and the controls necessary to ensure safety and effectiveness:

•Class I - Low Risk:

Requires general controls. Most are exempt from pre-approval (510(k)).

Examples: bandages, manual toothbrushes.

•Class II - Moderate Risk:

It requires general and special controls. It usually requires 510(k) submission.

Examples: infusion pumps, electric wheelchair.

• Class III - High Risk:

Critical or innovative devices. They require a rigourous pre-market process (PMA - Premarket Approval).

Examples: pacemakers, cardiac stents.

3. Classification according to the MDR (European Union)

With the entry into force of MDR Regulation (EU) 2017/745, the European Union updated its classes:

• Class I - Low Risk:

Examples: adhesives, spatulas, hospital beds.

•Class IIa - Moderate Risk:

Examples: contact lenses, infusion systems.

•Class IIb - High Risk:

Examples: ventilators, external defibrillators.

•Class III - Very High Risk:

Examples: active implantable devices, heart valves, vascular prostheses.

In addition, the MDR also introduces specific classifications for software as a medical device, highlighting its clinical and functional risk.

4. Classification of Medical Devices in Canada (Health Canada)

The Canadian system is regulated by Health Canada and follows a risk-based model with four classes (I to IV):

•Class I - Low Risk:

Simple devices, no need for a marketing license.

Examples: bandages, simple orthopaedic supports.

•Class II - Low to Moderate Risk:

Requires medical device license (MDL) and evidence of compliance.

Examples: syringes, manual surgical instruments.

• Class III - Moderate to High Risk:

You need a more robust technical dossier, with clinical evidence.

Examples: infusion pumps, diagnostic imaging devices.

•Class IV - High Risk:

It requires extensive documentation, including clinical studies.

Examples: pacemakers, implantable defibrillators.

5. Classification of Medical Devices in Australia (TGA)

In Australia, the Therapeutic Goods Administration (TGA) regulates medical devices following a risk-based system, very similar to that adopted by the European Union. The devices are classified from Class I (low risk) to Class III (high risk), with subdivisions for specific cases.

The classes are:

•Class I - Low risk:

Non-sterile, non-reusable devices, for external and transient use.

Examples: simple adhesive bandages, non-sterile examination gloves.

•Class Is - Class I sterile:

Same as Class I, but with sterility control requirement.

Examples: sterile gauzes.

• Class Im - Class I with measurement function:

Class I devices that accurately perform physiological measurements.

Examples: clinical thermometers.

• Class IIa - Moderate risk:

Short-term invasive devices or with low criticality therapeutic function.

Examples: nasal canulas, feeding probes.

•Class IIb - High risk:

Medium to long-term invasive devices or with influence on vital functions.

Examples: fans, haemodialysis devices.

•Class III - Very high risk:

Critical devices, often implantable or that support/do vital functions.

Examples: heart valves, pacemakers, neurological implants.

6. Classification of Medical Devices in the Eurasian Economic Union (UEEA)

UEEA regulation is based on Decision Nº 46/2017, which harmonises standards between member countries and adopts a system based on four risk classes, similar to the European model.

Categories and Classes:

•Class 1 - Low Risk:

Non-invasive devices, usually for external and transient use.

Examples: dressings, manual thermometers.

•Class 2a - Moderate Risk:

Devices with continuous use or indirect contact with the body.

Examples: diagnostic instruments, short-term catheters.

• Class 2b - High Risk:

Medium-term invasive or implantable products, with physiological impact.

Examples: respiratory support equipment, vital function monitors.

•Class 3 - Very High Risk:

Devices that sustain or maintain vital, long-term implantable functions.

Examples: cardiac prostheses, pacemakers, artificial valves.

Other relevant points:

•The approval is centralised, valid in all UEA member countries.

•Requires evidence of safety and efficacy, including technical, clinical evaluation and manufacturing inspection.

•The labelling must be in Russian and, where applicable, in the local languages of the member countries.