Evaluation Criteria and Guidelines

Pursuant to the 2nd amendment of the German Drinking Water Ordinance (TrinkwV), since December 2012 the German Environment Agency (Umweltbundesamt – UBA ) has been tasked with stipulating mandatory evaluation criteria for materials and substances that come into contact with drinking water. Previously, UBA has issued guidelines and recommendations which were less legally binding. Since the amendment of TrinkwV mentioned, these guidelines and recommendations have successively been implemented in the mandatory evaluation criteria.

UBA´s mandate to elaborate and to pursue evaluation criteria documents still is effective from the revised German Drinking Water Ordinance dated 20 June 2023. According to section 15 (2) of the TrinkwV, evaluation criteria documents become legally binding two years after they have been issued by UBA. After this date, for construction and maintenance of facilities for the abstraction, treatment and distribution of drinking water only materials that fulfill the requirements of these evaluation criteria must be used.

Accessible documents below will be updated in terms of applicable citations referring to the revised TrinkwV on the instant of pending amendments of the respective document.For certification (attestation of conformity) of products in contact with drinking water according to the evaluation criteria the German Environment Agency has set up a recommendation. An explanatory document adressing questions and answers (FAQ) in relation to the implementation of these regulatory documents can be found righthand within the Documents navigation box, which will be amended if required.

Transition from national to European requirements

The legal situation described above will be replaced in future by a new EU legal framework for materials in contact with drinking water.

UBA has prepared the following information to describe the transition from the national regulations to the future European requirements (REV02, October 2025):

• UBA information: Hygienic requirements for materials in contact with drinking water - New European regulation according to Directive (EU) 2020/2184

For metallic materials in contact with drinking water the following evaluation criteria document applies:

• Evaluation criteria for metallic materials (as at 21 August 2025)

The amendments can be reviewed in the German Federal Gazette (only in German):

• 6^th amendment of recasting as at 21 August 2025 (legally binding from 5 September 2027)
• 5^th amendment of recasting as at 5 March 2025 (legally binding from 15 March 2027)
• 4^th amendment of recasting as at 10 June 2024 (legally binding from 22 June 2026)
• 3^rd amendment of recasting as at 11 January 2023 (legally binding since 20 January 2025)
• 2^nd amendment of recasting as at 20 June 2022 (legally binding since 1 July 2024)
• 1^st amendment of recasting as at 25 May 2021(legally binding since 8 June 2023)
• recast as at 14 May 2020 (legally binding since 10 June 2022)

The evaluation criteria document comprises a positive list of metallic materials hygienically suitable for contact with drinking water. The German Environment Agency evaluates metallic materials in collaboration with relevant authorities of other EU member states that cooperate within the voluntary 4MSI collaboration (4MS-Initiative, started by four EU member states Germany, France, Netherlands and Great Britain). Metallic materials having been assessed this way are included in the 4MSI Composition List as well.

The below mentioned rules of procedure govern the positive list of metallic materials used for products in contact with drinking water contained in the evaluation criteria document.

Currently, product testing (according to e.g. DIN EN 16058) might be necessary to verify hygienic suitability for drinking water of factory soldered products and of products comprising platings not assignable to the scope of the evaluation criteria document for metallic materials. For such testing and the corresponding assessment, the following, currently non-binding, information has been prepared:

• Evaluation of factory soldered products in contact with drinking water
• Release of nickel by chrome-plated drinking water taps and other components

For enamels and ceramic materials in contact with drinking water the following evaluation criteria document applies:

• Evaluation criteria document for enamels and ceramic materials (as at 27 October 2025)

The amendments can be reviewed in the German Federal Gazette (only in German):

• 4th amendment as at 27 October 2025 (legally binding from 14 November 2027)
• 3^rd amendment as at 19 August 2024 (legally binding from 3 September 2026)
• 2^nd amendment as at 17 October 2023 (legally binding since 25 October 2025)
• 1^st amendment as at 6 August 2021 (legally binding since 26 August 2023)
• Initial version as at 5 August 2019 (legally binding since 12 September 2021)

To comprehend the rationale for reference concentrations as defined in the evaluation criteria document for enamels and ceramic materials, UBA has published an information:

• Information: Rationale for parameter values

To help with the process of consideration of new materials in the evaluation criteria document for enamels and ceramic materials, UBA has published an information.

• Information: Consideration of additional materials for inclusion in the evaluation criteria for enamels and ceramic materials in contact with drinking water

The German Environment Agency does not intend to define an evaluation criteria document for cementitious materials in contact with drinking water in anticipation of an European regulation. According to the revised European Drinking Water Directive (Directive (EU) 2020/2184), harmonized European requirements for materials in contact with drinking water will be defined. Until then, cementitious materials can be tested and evaluated according to DVGW-standard W 347. The German Environment Agency voluntarily offers as additional service to evaluate more starting substances not covered by DVGW-standard W 347. Evaluated starting substances are published in the information document below.

• Information on the evaluation of starting substances for cementitious materials in contact with drinking water

For plastics and other organic materials (coatings, lubricants, elastomers and thermoplastic elastomers) in contact with drinking water the following evaluation criteria document applies:

• Evaluation criteria document for plastics and other organic materials (as at 27 October 2025)
• Polymer-specific annexes to the Evaluation criteria document for plastics and other organic materials (as at 27 October 2025)

The amendments can be reviewed in the German Federal Gazette (only in German):

• 6th amendment as at 27 October 2025(legally binding from 14 November 2027)
• 5th amendment as at 24 February 2025 
• 4th amendment as at 23 August 2024 (legally binding from 13 September 2026
• 3rd amendment as at 7 March 2022 (legally binding since 17 March 2024)
• 2nd amendment as at 9 March 2021 (legally binding since 20 March 2023)
• 1st amendment as at 14 May 2020 (legally binding since 21 May 2022)
• Initial version as at 11 March 2019 (legally binding since 21 March 2021)

For the transition from UBA guidelines to KTW evaluation criteria the German Environment Agency has set up the following transitional regulation:

• Transition from UBA guidelines to the evaluation criteria document for plastics and other organic materials in contact with drinking water (transitional regulation KTW-BWGL)

One prerequisite for being tested according to the evaluation criteria document is that starting substances to be employed are evaluated and listed in the respective polymer-specific positive list. The German Environment Agency evaluates drinking water hygienic suitability of starting substances for organic materials in cooperation with the German Federal Institute for Risk Assessment (Bundesinstitut für Risikobewertung, BfR).  From enacting the revised European Drinking Water Directive and its subsequent national implementation as revised German Drinking Water Ordinance (TrinkwV), ECHA and the Member States participating in the 4MSI collaboration will be informed about the recent assessment of a starting substance.

For the management of positive lists of starting substances for organic materials of the evaluation criteria documents, the rules of procedure mentioned below apply.

The KTW Guideline, Coating Guideline and Lubricants Guideline have been withdrawn on 21 March 2021.

Silicones hitherto have been regulated within the KTW Guideline and are not yet covered by the Evaluation criteria document for plastics and other organic materials in contact with drinking water. For this reason, the following transitional recommendation applies:

• Transitional Recommendation for Silicones

The valid version of the Elastomer Guideline dates from 16 March 2016 and will be withdrawn on 1  July 2026.

• Elastomer Guideline

The valid positive list of the starting substances is included in Annex D of the KTW evaluation criteria document.

• Polymer-specific annexes to the Evaluation criteria document for plastics and other organic materials (only available in German)

For some materials the formula-specific requirements concerning migration into drinking water can be computed mathematically by using the Modelling Guideline, rather than being substantiated analytically.

The De Minimis Guideline can additionally be used as a basis for formulation assessment for substances that are used in small amounts and that have specific technological functions.

UBA has transposed the Elastomer Guideline and the TPE transitional regulation into the KTW evaluation criteria document.

• Information on transposition of Elastomer Guideline and TPE transitional regulation into the KTW evaluation criteria document

Hitherto thermoplastic elastomers could be assessed using the transitional recommendation for hygienic assessment of thermoplastic elastomers (TPE Transitional Recommendation).

The document version currently valid dates from 11 March 2019 and will be withdrawn on 1 July 2026.

• Transitional Recommendation for thermoplastic elastomers

By having transposed the Elastomer Guideline and the TPE transitional regulation into the KTW evaluation criteria document, UBA has also rearranged hygienic assessment of thermoplastic elastomers.

• Information on transposition of Elastomer Guideline and TPE transitional regulation into the KTW evaluation criteria document

The recommendation titled: “Assessment of substances with a specific technological function and low required quantities relating to the formulation review in accordance with the guidelines of the German Environment Agency on the hygienic assessment of organic materials in contact with drinking water (De Minimis Guideline)” was published in the 2012 issue of Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz (55:150-151).

The valid version of the De Minimis guideline dates from 18 April 2011 and will be withdrawn on 1 July 2026.

• De Minimis Guideline

This guideline can be used in conjunction with the still existing documents Elastomer Guideline and transitional recommendation for TPE to evaluate formulations for manufacturing organic materials in contact with drinking water.

The Guideline for the Mathematical Estimate of the Migration of Individual Substances from Organic Material in Drinking Water (Modelling Guideline) was published in the February 2025 issue of Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2025 ∙ 68:219-228.

The valid version is the one dated 3 December 2024.

• Modelling Guideline 
• Annex to the Modelling Guideline (only available in German)

The Modelling Guideline enables the testing of formulation- and substance-specific requirements pursuant to the Evaluation Criteria for plastics and other organic materials in contact with drinking water (KTW-BWGL), using mathematical modelling. Following this, experimental testing concerning these requirements is not necessary.

The German Environment Agency has published the „Recommendation for attestation of conformity of product hygiene suitability for drinking water“:

• Recommendation for attestation of conformity of product hygiene suitability for drinking water

The German Environmental Agency is mandated to publish evaluation criteria documents for drinking water contact materials pursuant to section 15 (1) of the TrinkwV. These legally binding evaluation criteria do not include determinations regarding to the manner of attestation of conformity for products intended to come into contact with drinking water. As endorsement to evaluation criteria documents, the German Environment Agency, in cooperation with expert groups and after having passed a hearing process, have prepared a recommendation for attestation of conformity of product hygiene suitability for drinking water.

The recommendation for attestation of conformity of product hygiene suitability for drinking water had been amended before in April and July 2020 (1st and 2nd amendment, respectively) and has been updated in July 2021 by the current 3rd amendment.

In order to standardise necessary product-related specifications in issued certificates, UBA has elaborated an attachment to this Recommendation providing templates for certificates:

• Attachment to the Recommendation: Templates for certificates according to evaluation criteria of the German Environment Agency (German version only)

Explanations for implementation of this recommendation in certification processes for products in contact with drinking water following evaluation criteria are provided in an FAQ document, see navigation box 'Documents'.

For the management of the positive list of metallic materials hygienically suitable for the contact with drinking water as implemented in the evaluation criteria document for metallic materials in contact with drinking water, the following rules of procedure apply:

• Rules of Procedure of the German Environment Agency for the management of the positive list of metallic materials hygienically suitable for drinking water
• Annex 1: Application for the inclusion of a material in the positive list of the evaluation criteria for metallic materials in contact with drinking water

For the management of positive lists of starting substances for Evaluation criteria for plastics and other organic materials in contact with drinking water, the following rules of procedure apply:

• Rules of Procedure of the German Environment Agency for the management of the positive list of starting substances for organic materials in contact with drinking water

The appendixes can be downloaded separately:

• Annex 1: Application for inclusion of a starting substance in the positive list of starting substances for organic materials in contact with drinking water
• Annex 2: Supplementary application form for the inclusion of a not completely assessed substance
• Annex 3: Supplementary application form for the inclusion of a substance which is already assessed by EFSA
• Annex 4: Supplementary application form for the inclusion of a substance which is already assessed by another authority or international organization