ISO 15223: The Symbols Standard for Medical Device Labels

Introduction

ISO 15223 is the reason a device label can say almost nothing in words and still say everything a regulator requires. Under MDR Annex I, a single label has to carry the manufacturer's identity, the lot number, the sterilisation method, whether the device contains a CMR substance, whether it may be reused, and half a dozen other facts — on a surface the size of a coin, in every language the device ships to. Symbols are not a design choice here. They are the only way the requirement is physically satisfiable.

What trips manufacturers up is treating the standard as a clip-art library. ISO 15223-1 is a normative document: every symbol has a reference number, a defined meaning, sizing requirements, and in many cases a restriction on where it can be used without an accompanying explanation. A symbol that looks right but was not sourced from the standard's own tables carries no regulatory weight, however intuitive it seems. Getting this right also intersects directly with the GSPR checklist and with the broader EU MDR technical documentation the labelling section has to sit inside.

This article works through what the standard actually specifies: how a symbol entry is structured, the general requirements every symbol must meet, what changed in the current 2021 edition, the amendment now running through its transition period, when a symbol still needs a text explanation, and the labelling errors that keep showing up in Notified Body reviews.

Table of Contents

• Why MDR Annex I forces every manufacturer into ISO 15223
• How the standard defines a symbol: the seven-column entry
• The general requirements every symbol has to satisfy
• The families of symbols, and what belongs in each
• Fifteen symbols to know at a glance
• What changed in the 2021 fourth edition
• Amendment 1:2025: EC REP becomes EU REP
• When a symbol still needs a text explanation
• Where ISO 15223 stops, and the misuse that starts there
• The findings that keep recurring
• Frequently asked questions
• Conclusions

Why MDR Annex I forces every manufacturer into ISO 15223

Annex I, Section 23.2 of Regulation (EU) 2017/745 lists what has to appear on the label, and it is a long list even before translation is considered: the manufacturer's name and address, the lot or serial number, the shelf life or date of manufacture, storage conditions, the fact that the device is a medical device, whether it contains a medicinal product, whether it contains tissue or cells of human or animal origin, whether it contains a substance classified as carcinogenic, mutagenic or reprotoxic (CMR) or as an endocrine disruptor, whether it has been sterilised, whether it is intended for single use, and the authorised representative where applicable. Section 23.4 adds parallel requirements for the instructions for use.

None of that text is optional, and Section 23.1(h) is explicit that internationally recognised symbols are to be used, where they exist, to convey this information. That single clause is what makes ISO 15223-1 load-bearing rather than optional best practice: a manufacturer who writes "sterilised using ethylene oxide" out in full on a label that also needs the same information in eighteen EU languages will run out of physical space long before running out of words. IVDR Annex I, Section 20.3, imposes the equivalent obligation for in vitro diagnostic devices, with a small number of IVD-specific additions such as the rapid-test self-testing restriction.

The standard's own title states its scope precisely: symbols to be used with information to be supplied by the manufacturer, applicable directly on the device, on its packaging, or in the accompanying documentation. It does not, on its own, tell a manufacturer which pieces of information are mandatory — that comes from the regulation. What it supplies is the vocabulary: a symbol for each Annex I requirement that has one, with a defined graphic, a defined meaning and defined conditions of use.

How the standard defines a symbol: the seven-column entry

Every symbol in ISO 15223-1 is documented the same way, and understanding that structure is what separates a defensible symbol choice from a guess. Each entry in the standard's tables carries seven pieces of information: a reference number and the graphic itself, a title, a description of what the symbol conveys, the requirements for its use, explanatory notes, any restriction of use, and the underlying ISO/IEC symbol register number with its registration date — because most ISO 15223-1 symbols are not invented by this standard but drawn from the ISO 7000 register of graphical symbols for equipment, which predates and extends beyond medical devices.

The requirements and restriction-of-use columns are where manufacturers lose points most often, because they read like footnotes and are treated as such. They are not footnotes. The authorised representative symbol, for example, carries a requirement that it be accompanied by the representative's name and address immediately adjacent — a requirement Amendment 1:2025 restated explicitly in a revised Clause 5.1.2 precisely because it was being missed.

The general requirements every symbol has to satisfy

Clause 4 of ISO 15223-1 sets requirements that apply across every symbol in the catalogue, independent of which one is being used. Three matter in practice more than the rest.

Size is governed by legibility, not by a fixed millimetre value. The 2021 edition changed the wording from the manufacturer "shall" to the manufacturer "must" determine the appropriate size — a small change in modal verb that shifts the burden onto the manufacturer to justify the size chosen for the actual viewing distance and printing method, rather than defaulting to whatever fits. A symbol that is technically present but not legible at arm's length on a small-diameter device satisfies the letter of the requirement and fails its purpose, and a reviewer is entitled to ask for the legibility rationale.

Colour is not prescribed by the standard itself in most cases; where colour carries meaning — as in safety-related pictograms drawn from other standards — that meaning is fixed by the source standard, not by ISO 15223-1. Using the standard's own black-on-white symbols in a colour scheme that implies urgency or safety significance they were not designed to carry is a misuse the standard does not license.

Single point of reference is the principle behind the requirement, noted above, that identification symbols be placed adjacent to the name and address they refer to, rather than scattered across the label with the text information in a different location. Amendment 1:2025 extended this logic: where the name and address of two different roles — the manufacturer and the authorised representative, for instance — happen to be identical, the amendment now permits grouping every applicable role symbol next to the single address block instead of repeating the block for each symbol.

The families of symbols, and what belongs in each

ISO 15223-1 does not organise its tables around a rigid taxonomy, but in practice the several hundred symbols it now contains group into a small number of functional families, and the family a symbol belongs to is a reliable predictor of how strict its explanation rule will be. Identification and regulatory-role symbols — manufacturer, date of manufacture, authorised representative, importer — establish who is accountable for the device. Sterility and reusability symbols carry some of the highest-consequence information on the label, since using a single-use device twice or a non-sterile device as if it were sterile is a direct patient-safety failure. Storage, transport and handling symbols communicate environmental limits that, if exceeded silently, degrade performance without any visible sign. Biological and chemical hazard symbols flag substances that change the device's risk classification and its clinical evaluation. And a residual family identifies the device itself — medical device, IVD medical device, the unique device identifier — and points the reader to the instructions for use.

The distinction matters because it is the family, not the individual symbol, that a labelling review checks first. A missing sterility symbol on a sterile device is a different order of finding from an imprecisely sized manufacturer symbol, and a labelling procedure that treats every symbol as equally interchangeable will not catch that difference before a reviewer does.

Fifteen symbols to know at a glance

These are the symbols that appear on the overwhelming majority of device labels, shown here exactly as registered in ISO 15223-1, with the standard's own clause number. The authoritative artwork remains the ISO 7000 register and the standard itself — pull the master files from there for production artwork rather than a screenshot.

What changed in the 2021 fourth edition

ISO 15223-1:2021 replaced the 2016 third edition and is the current edition referenced by EU MDR Annex I, harmonised in the EU's list of harmonised standards from January 2022. Manufacturers still working from a 2016-vintage symbol library are working from a withdrawn edition, and the gap between the two is not cosmetic.

The fourth edition added twenty-five new symbols to the catalogue, closing gaps that had previously forced manufacturers into free text or into borrowing symbols from adjacent standards without a proper basis for doing so. It updated the underlying definitions to align with ISO 20417 (information to be supplied by the manufacturer), ISO 14971 (risk management) and ISO 13485 (quality management), so that a term like "intended purpose" means the same thing across the documents a technical file has to reference consistently. It reworded the general requirements of Clause 4.2, including the size-determination change described above. It substantially extended the informative Annex A with notes and worked examples, including guidance on combining several symbols in a single label area without creating ambiguity. And it added the informative annexes mapping the standard directly against the general safety and performance requirements of both the MDR and the IVDR — Annexes ZA and ZB — which is what allows a manufacturer to cite ISO 15223-1 compliance as contributing evidence against a specific GSPR rather than as a general good-practice gesture.

The GSPR-mapping annexes are the reason ISO 15223-1 shows up in a technical file's GSPR checklist by reference number, not just by name — a reviewer checking conformity to Annex I Section 23 can trace a specific symbol straight back to the specific sub-requirement it satisfies.

Amendment 1:2025: EC REP becomes EU REP

ISO 15223-1:2021/Amendment 1:2025 is the live development in this standard, and it is worth tracking closely because it is mid-transition right now. The amendment, published by ISO on 5 March 2025, replaces the authorised representative symbol's "EC REP" text element with "EU REP", and formally defines "authorised representative" as a term for the first time. The reason is more substantive than it first appears: ISO 3166-1's two-letter country code for Ecuador is also "EC", and a symbol intended to mean "European Community representative" was, on a literal reading, indistinguishable from a country code for a South American state. The amendment also generalises the symbol so the bracketed code is no longer fixed to Europe: it takes a two- or three-letter jurisdiction code recognised by the relevant authority, which is what makes the same symbol usable for an authorised representative in the UK, Switzerland, or any other jurisdiction that adopts the convention.

The amendment reached harmonisation for both the MDR and the IVDR when the European Commission published the reference to EN ISO 15223-1:2021/A1:2025 in the Official Journal of the EU on 17 June 2026. That harmonisation carries a five-year transition period, running to 17 June 2031, during which both the EC REP and EU REP symbols remain valid on the market. There is no cliff-edge deadline forcing an immediate relabel, but there is also no reason to wait until year four to plan the changeover: any manufacturer scheduling a label revision for other reasons between now and 2031 should fold the EU REP change into that revision rather than treat it as a separate project later.

When a symbol still needs a text explanation

Harmonisation under the MDR or IVDR creates a presumption of conformity, and a common shortcut is to treat that presumption as meaning symbols never need explaining once the standard is harmonised. That is not what the standard or the regulation says. Clause 4.2 conditions the presumption: where the device is intended, even in part, for lay users, the symbols used still have to be explained, because comprehension without explanation cannot be assumed for a lay population regardless of how internationally recognised the pictogram is. For professional users, the presumption holds more readily, but it is rebuttable — a usability evaluation that surfaces actual misunderstanding of a specific symbol by the actual user group overrides the presumption, harmonisation notwithstanding.

This is also where a symbol's own restriction-of-use note does real work. Some entries in the standard's tables carry an explicit restriction requiring explanation regardless of user population; skipping that column because it "usually says none" is how those specific requirements get missed. A labelling procedure that checks the restriction-of-use field for every symbol used, not just for the symbols that look unfamiliar, closes this gap systematically instead of case by case.

Where ISO 15223 stops, and the misuse that starts there

ISO 15223-1 is explicit that its requirements are not intended to apply to symbols specified in other standards, and that boundary gets crossed more often than the size or colour rules do. IEC 60601-1, the general standard for medical electrical equipment, has its own mandatory action sign — the blue circular "consult instructions for use" pictogram, formally ISO 7010-M002 — with its own trigger condition in Clause 7.2.3: it is required specifically where the instructions for use function as a primary risk control measure for the device. Using that sign interchangeably with the ISO 15223-1 "consult instructions for use" symbol, which has no such trigger condition, treats two different regulatory instruments as one and typically results in the wrong sign being used, or the right sign being used for the wrong reason.

The same boundary applies to safety-relevant signage more generally, including the broader family of hazard and mandatory-action pictograms in ISO 7010. A device may legitimately need symbols from more than one standard on the same label — ISO 15223-1 for the regulatory information the MDR requires, IEC 60601-1 or ISO 7010 for equipment-specific safety warnings — but each family carries its own rules for size, colour and explanation, and importing one family's assumptions into another is a documented source of Notified Body findings. Where a symbol communicates safety-critical information and is not covered by ISO 15223-1 at all, the risk management process referenced in the ISO 14971 risk management file is what should be driving the choice, not visual habit.

The findings that keep recurring

Six patterns account for most of the labelling-related observations that come out of Notified Body technical file reviews and internal audits against Clause 4.2.3 of ISO 13485. None of them is exotic; all of them are avoidable with a labelling procedure that checks the standard's own columns rather than relying on what the last product's label looked like.

Frequently asked questions

What is ISO 15223 and why is it needed?

ISO 15223-1 is the international standard that defines the graphical symbols manufacturers use on medical device labels, packaging and accompanying information in place of text. It exists because MDR Annex I Section 23.1(h) requires internationally recognised symbols to be used where they are available, and because label space and multi-language requirements make full text impractical for a device sold across many countries.

What is the difference between ISO 15223-1 and ISO 15223-2?

ISO 15223-1 lists the symbols themselves, with their meaning and conditions of use, and is the part referenced by the MDR and IVDR. ISO 15223-2 is a separate, methodological document covering how new symbols are developed, selected and validated for comprehension before they are proposed for inclusion in Part 1. Most manufacturers only ever need Part 1.

Is ISO 15223-1:2021 harmonised under the EU MDR and IVDR?

Yes. EN ISO 15223-1:2021 was added to the EU's list of harmonised standards in January 2022, which gives it the presumption of conformity with the relevant GSPRs when correctly applied. Amendment 1:2025 reached harmonised status separately, with its reference published in the Official Journal on 17 June 2026 and a five-year transition running to 2031.

Do I have to explain every ISO 15223-1 symbol in the instructions for use?

Not automatically, but the presumption that you do not is conditional, not blanket. Symbols must be explained where the device is intended for lay users, where a usability evaluation shows the target population does not actually understand a specific symbol, and wherever the standard's own restriction-of-use column requires it regardless of user type.

What changed with ISO 15223-1:2021/Amd 1:2025 and the EC REP symbol?

The amendment replaces the "EC REP" text in the authorised representative symbol with "EU REP" for the EU, generalises the symbol to take any recognised jurisdiction code, and formally defines "authorised representative" in the standard. It was harmonised in the OJEU on 17 June 2026 for both the MDR and the IVDR, with both the old and new symbols valid throughout a five-year transition to 17 June 2031.

Is ISO 15223-1:2021 recognized by the FDA?

Yes. ISO 15223-1:2021, including Amendment 1:2025, appears in the FDA's Recognized Consensus Standards database, so a manufacturer can cite a declaration of conformity to it in a premarket submission. Recognition is a separate process from EU harmonisation and follows its own database entry and any FDA-specific transition conditions.

Can I use a symbol not listed in ISO 15223-1 on my label?

Only where no equivalent symbol exists in the standard, and in that case the information generally has to be conveyed in text instead, or through a symbol properly sourced from the specific standard that governs it — a product-specific safety sign from IEC 60601-1, for example. An invented pictogram carries no presumption of comprehension and no regulatory basis, whatever it looks like.

Where do I find the actual symbol graphics?

The authoritative source is the ISO Online Browsing Platform, where ISO 15223-1 can be consulted, and the ISO 7000 register that most of its symbols are drawn from. Several industry associations, including MedTech Europe, publish free reference guides reproducing the more commonly used symbols for quick lookup, though the standard itself remains the normative source for any dispute.

Conclusions

Treat ISO 15223-1 as a controlled reference table, not a symbol library to browse by eye. Every symbol used on a label should be traceable to a specific reference number in the current 2021 edition, checked against the requirements and restriction-of-use columns for that entry, sized on a documented legibility rationale, and explained in the IFU wherever the device's user population or a usability finding requires it. The EU REP transition is the one item on this list with a clock already running, even at five years, so it belongs on the label revision plan now rather than on a future one.

The Labelling and Translation Management package on MD Regulatory turns this into a documented procedure — mapped to MDR Annex I Section 23, ISO 15223-1 and ISO 20417 — that sits inside an existing EU MDR technical documentation structure and an IVDR one alike.

Related articles

• GSPR Checklist: All 23 EU MDR Annex I Requirements
• EU MDR Technical Documentation Requirements: Complete Guide to Annex II and III
• ISO 13485:2016 — The Complete Guide to Medical Device Quality Management
• ISO 14971 Risk Management for Medical Devices
• IVDR Explained: What Regulation (EU) 2017/746 Requires