UDI Laser Marking: What to Consider for Class I Medical Devices until Sept 24, 2022

Laser marking on dental and other medical devices: FOBA answers some frequent questions in view of the upcoming last FDA implementation deadline.

[Translate to English:] Dentalspiegel, laserbeschriftet mit UDI Code

From September 24, 2022, any reusable and reprocessed medical devices on the U.S. market must bear a UDI direct mark according to the FDA regulations. After risk classes III and II, this will then also affect class I products such as surgical instruments, dental probes, medical drills and many more.

Regarding the upcoming deadline, FOBA offers support for a compliant technical implementation of industrial laser marking. Namely, the directly marked UDI code must meet quality criteria that ensure permanent readability of the UDI during multiple reprocessing. Likewise, the marking process must be fully validated, and the UDI must be registered via the GUDID database.

Manufacturers who have already taken UDI measures required for the U.S. are well positioned for the MDR regulations just starting in Europe. But many still face the complex validation and EUDAMED registration for Europe as well. Thus, time pressure is increasing, and at the same time, there are still many ambiguities regarding a proper implementation of direct labeling.

We have compiled a selection of the frequent questions and answers, originating from webinars and from the close cooperation between FOBA's laser marking experts and many medical technology manufacturers:

Does the expiry date of a medical device have to be included in the UDI?

The UDI consists of two main components:

- the DI (Device Identification, e.g. as GTIN) stands for a worldwide uniquely defined product type
- followed by the PI (Production Identification), which identifies a single product individually.

The expiry date must always be specified in the PI-UDI. If no expiry date is available, the production date must be specified.

In addition, the PI-UDI includes the following mandatory components:

- Batch number (batch or lot number)
- Serial number (if available; if possible, batch and serial number)
- Software identification, if applicable

What quality standards must a laser marked UDI meet?

According to the FDA, the verification of the code should achieve at least quality grade C, better B or A. This must be guaranteed throughout the entire life cycle, i.e. even after multiple reprocessings of a product.

The readability of the code can be further improved by a lightened background. The laser process used to first lighten the background is called frosting.

If the spaces and the background of a data matrix code are marked in white besides the black parts, this is called black-and-white marking. Both are common techniques to increase contrast and legibility.

Does a UDI also have to be marked directly on very small products (e.g. rotary dental FG drills with 1.6 mm diameter that are reprocessed)?

In principle, direct marking is mandatory for any reprocessed class I products. Thus, the UDI marked on the product must also comply with the generally required form, i.e., be presented both in plain text and as a machine-readable code.

However, there are exceptions:

  • if the marking affects the safety or performance of the device, or
  • if the application is technically not feasible.

In which cases is the technical implementation of UDI marking not feasible?

If there is not enough space to mark the full code format (i.e. human and machine readable), at least the AIDC ("Automatic Identification and Data Capture") format must be applied.

If the space on the product surface is so tight that even the minimum size for the machine-readable UDI code cannot be met, marking is technically not feasible.

However, it must then be explained in the technical documentation that the space is not sufficient. In addition, the complete UDI must at least be applied to the packaging as well as outer packaging of the product.

How small can/may a UDI code be, so what is the minimum size for marking?

The machine-readable UDI can be represented either as a data matrix or as a linear barcode. Data matrix codes require the least space, while barcodes require more space for the same density of information.

To ensure the required readability of the AIDC code by means of a code verifier, there are minimum module sizes for data matrix codes. In laser marked GS1-standardized codes, for example, the smallest module size is 0.1 mm (0.0039 inches). The total width and height of the DMC is then measured in each case according to the amount of encoded data plus the bright zone added on all four sides of one module width each.

For ink-based code marking, GS1 specifies a minimum X-module size of 0.254 mm (0.1 inches) since the contrast sharpness achieved here is lower than with laser marking.

What is a practical size of a data matrix code?

FOBA generally recommends a DMC area size of approx. 2.5 x 2.5 mm (0.0984 x 0.0984 inches) and above. This ensures that largely all types of verifiers can capture the code.

In this way, quality control then also works in the dental practice with readers that are simpler compared to the verifiers used in industrial production.

Read also other FOBA blog articles with detailed information about Data matrix codes:

Facts about Data Matrix Codes for
Product Identification (Part 1)

How to Optimize Data Matrix Codes
(Part 2)


By when must medical devices be entered into the EUDAMED database?

After the MDR came into force on May 26, 2021, the commissioning of the EUDAMED database and the obligation to register there was postponed to May 26, 2022, due to the Corona crisis and bottlenecks at the Notified Bodies. In principle, all new products placed on the market must receive a UDI and be registered there from this date.

For products that have already been on the market for a longer period of time, there is a transitional period until May 26, 2024. This extension of the deadline allows "old products" to remain on the market provided that a declaration of conformity has been drawn up for Class I products with the assistance of a notified body before May 26, 2021. In the same way, other devices for which valid certificates already exist in due time are still allowed according to the requirements of MDD 93/42/EEC.

But: Existing products must still be entered in the EUDAMED database. However, these do not yet require a UDI for this. To be able to register them in a system-compliant manner anyway, they receive specially assigned identification numbers from EUDAMED.

When should one start the implementation of direct marking?

According to MDR requirements, for example, UDI direct marking of Class III devices is not mandatory until May 2023. However, you must factor in that the entire process to implement the best possible marking solution can take several months.

Machine and process validation account for the largest share of time. Therefore, good preparation and planning for responsibilities of tasks in advance are important for a timely implementation and validation.

Can FOBA provide the validation of the marking process together with the marking system?

FOBA supports its customers with IQ-OQ-PQ-MQ but cannot and must not offer validation of the process itself. This needs to be done directly at the respective production site. An experienced external validation partner can be a reliable support, and FOBA will be happy to connect with respective experts.

It should be noted that validation must be repeated about every three years. In certain cases, such as in the case of a machine movement, additional validation will even be required due to possible changes in lighting conditions or other determinants.