When placing products in contact with drinking water on the EU market, manufacturers will encounter different types of certificates issued by conformity assessment bodies. These certificates reflect the stage of the product (final, intermediate, or pre-product) and the type of assessment carried out. Understanding which certificate applies to your product is key to planning compliance efficiently.
Note, not all certificates are covered by EU 2024/370. And not all products can hold the EU DWD mark. But all certificates play an important role. Below we want to cover the most important certificates – and we will also clearly indicate if these mean that for the product in question you can use the DWD mark.
Product Certificates
A product certificate is the standard outcome for a single product, which may also be an assembled product. It confirms that the specific product has been tested and assessed according to the relevant conformity modules (Module B + C or Module B + D). The certificate must clearly specify the product covered, the production site(s), the assessed product group, and the conformity procedure applied.
Can use the DWD mark = YES
Product Type Series Certificates
Where a manufacturer produces a series of related or assembled products, these can be covered together by a product type series certificate. This approach reduces duplication, as one certificate can apply to multiple similar products and production sites. As with product certificates, the document must specify the covered products, assessed group, and conformity route. These are performed under Module B and either Module C or Module D.
Can use the DWD mark = YES
Component Certificates
In cases where groups of components (for example, valves, taps, or fittings) are used across different assembled products, a component certificate may be issued. This certificate lists all covered components and production sites and links them to the appropriate product group and conformity modules. Importantly, components certified in this way can be used across different products and even different manufacturers, simplifying downstream approvals.
Can use the DWD mark = YES
Pre-Product, Intermediate Product, and Constituent Certificates
Not all certificates are issued for final products. To support the supply chain, conformity assessment bodies may issue certificates for pre-products (e.g. granulates or raw materials), intermediate products (e.g. adhesives, coatings, ready-to-use cementitious mixes), and constituent products used for cementitious materials. These are issued as pre-assessments based on testing of standardised test pieces of the final material. They do not allow EU marking under CDR (EU) 2024/371 but are highly recommended: holding such certificates makes it easier for downstream manufacturers to demonstrate compliance without repeating tests.
Can use the DWD mark = NO. They are very useful to get from a Notified Body to help your different buyers, because all your buyers must still show to the Notified Body that you comply.
Formulation Certificates
Finally, a formulation certificate may be issued for a specific recipe of a material. This certificate only covers the formulation review — no testing is included. It specifies the identity or number of substances that must be analysed during migration testing and only becomes valid once these details can be shared with other notified bodies. Again, these certificates are pre-assessments and not sufficient for marking but play an important role in reducing duplication further down the supply chain.
Can use the DWD mark = NO, same principle as above on pre-products.
Important Notes for Manufacturers
- Only product, product type series, and component certificates allow EU marking with the DWCM symbol.
- Pre-product, intermediate, constituent, and formulation certificates are not issued under Regulation (EU) 2024/370 and cannot carry the DWD mark, but they provide valuable pre-assessments that simplify final product approvals.
- Certificates must always include key details: manufacturer’s name and address, conformity assessment conclusion, applicable product group, conditions of use, temperature classes (23°C, 60°C, 85°C), and identification data for the approved type. Family certificates must also list identifiers such as pipe sizes.
- One certificate may cover multiple production sites if they operate under the same entity and quality management system.
- Using alternative suppliers for uncertified pre-products or constituents may require additional testing.