Symbols on medical devices are graphical signs that represent manufacturer information on the product, its packaging, or in the accompanying information without the use of text. The legal basis is Annex I, Chapter III, Section 23.1, point (h) of Regulation (EU) 2017/745: where appropriate, internationally recognized symbols that comply with harmonized standards or common specifications shall be used; if such standards or specifications do not exist, the symbols used must be explained in the accompanying documentation. The relevant standard is EN ISO 15223-1, which specifies symbols for the information to be provided by the manufacturer. Symbols thus partially replace language versions, but do not reduce the responsibility for comprehensibility.
Normative Basis
ISO 15223-1, 2021 edition, is titled “Symbols to be used with information to be supplied by the manufacturer” and is the fourth edition of the standard. It was listed by the European Commission in January 2022 as a harmonized standard under Regulation (EU) 2017/745 and Regulation (EU) 2017/746, and is available as DIN EN ISO 15223-1:2022 in the German version. Compared to the previous edition, it contains approximately 25 additional symbols.
The standard is structured into a normative part with terms and requirements, extensive symbol tables, and informative annexes. Annexes ZA and ZB map the symbols to the requirements of the two Regulations, thereby facilitating proof of which symbol addresses which legal obligation.
Structure of the Symbol Tables
Each table entry contains a reference number and graphic, the title of the symbol, a description, the requirements for its use, notes, any restrictions on use, and the registration number and date in the ISO 7000 or IEC 60417 database. For example, the symbol for the manufacturer with reference 5.1.1 requires that it appears immediately next to the name and address of the manufacturer; it is registered under number ISO 7000-3082.
Typical Symbol Groups
Practically relevant symbols primarily include those for identifying the manufacturer, authorized representative, importer, and distributor, as well as batch and serial numbers, catalog number and date of manufacture, use-by date, sterile condition with indication of the sterilization method, single-use, prohibition of re-sterilization, storage and transport conditions such as temperature and humidity limits, and the reference to the instructions for use.
In addition, there is the symbol indicating that the product is a medical device, which reflects the corresponding mandatory information according to Annex I, Chapter III, Section 23.2. For information for which no standardized symbol exists, text or an explained proprietary graphic remains necessary.
Duty of Explanation and Usability
Since EN ISO 15223-1 is harmonized, the symbols listed there do not necessarily have to be explained in the instructions for use in every case. However, an explanation remains required if its absence increases the risk of misuse. Whether this is the case should be demonstrated through a usability assessment with the intended user group, rather than being assumed as a general rule.
For products intended for lay users, an explanation is required throughout, as knowledge of symbols cannot be assumed. Additionally, the industry association MedTech Europe publishes a freely available guide that summarizes common labeling symbols and their use.
Distinction from CE Marking, Product Identification, and Warning Symbols
The CE marking according to Article 20 is not an information symbol within the meaning of the standard, but rather the conformity mark with its own design and application rules, which may be accompanied by the identification number of the Notified Body. The carrier of the Unique Device Identification (UDI) is also not a symbol, but a machine- and human-readable code according to Article 27 and Annex VI.
Finally, safety signs and warning symbols from other standards, as well as symbols for electrical equipment following their own sets of rules, must be distinguished from the information symbols in the series of standards. Anyone combining symbols from different sources must ensure their meaning remains consistent and must name the standards used in the technical documentation.
Relevance for clinical trials
Investigational products are also labeled, and their labeling largely uses the same symbols for batch, use-by date, sterility, and storage conditions. The indication that the product is intended exclusively for clinical investigations must be unmistakably recognizable to the site personnel to ensure that accidental use outside the trial is excluded. Misinterpreted storage or processing symbols are a frequent cause of avoidable protocol deviations.
For usability studies, symbols are also a separate subject of testing, as their comprehensibility within the target group must be proven if they are intended to replace textual warnings. Full-service CROs like Mediconomics support sponsors and manufacturers in reviewing symbol usage and labeling of investigational products, aligning site training accordingly, and feeding findings on misinterpretations back into the product information in a documented manner.
Frequently Asked Questions (FAQ)
Is the use of symbols mandatory?
Annex I, Chapter III, Section 23.1, point (h) requires internationally recognized symbols where appropriate. There is therefore no blanket requirement, but there is a burden of justification if established symbols are not used.
Do all symbols have to be explained in the instructions for use?
Symbols from the harmonized standard do not necessarily have to be explained. An explanation is required if its absence increases risks, and is required throughout for lay users.
Which edition of the standard should be applied?
The harmonized version EN ISO 15223-1:2021, published in Germany as DIN EN ISO 15223-1:2022, is authoritative. The currently listed status must be checked before the labeling is released.
Regulatory References
- Regulation (EU) 2017/745, Annex I, Chapter III, Section 23.1, point (h) — Use of internationally recognized symbols
- Regulation (EU) 2017/745, Annex I, Chapter III, Section 23.2 — Mandatory information that can be represented by symbols
- EN ISO 15223-1:2021 or DIN EN ISO 15223-1:2022 — Symbols to be used with information to be supplied by the manufacturer
- Regulation (EU) 2017/745, Article 20 — CE marking as a standalone conformity mark
- ISO 7000 and IEC 60417 — Registration databases of graphical symbols for use on equipment
