Compounds for use in drinking water applications

The new KRAIBURG Pure compound series is an innovative and efficient solution for cold, warm, and hot water applications, such as seals, fittings, or mechanical and plant engineering. The EPDM compounds are in accordance with new regulations applicable after 2021 and have various approvals confirming their suitability for use in drinking water applications.

In addition to the requirements of the Elastomer Guideline applicable after 2021, the compound series also meets the specifications of the Evaluation Criteria Document for Plastics and other Organic Materials in Contact with Drinking Water (KTW-BWGL) Annex D, which will apply from March 1st, 2025 and replace the Elastomer Guideline.


✓ Applications: cold and warm water

✓ Hardness range: 50 to 85 Shore A

✓ Can be processed in compression, transfer and injection molding processes

✓ EN 16421, WRAS and ACS approval

✓ Suitable for use in accordance with the KTW-BWGL applicable as of 03/01/2025

✓ UBA-ELL-Type test on 2 mm test plate

✓ Formulation according to FDA §177.2600 positive list

✓ Fulfills 3-A Sanitary requirements


D        EN 16421

Suitable for type test in accordance with the KTW-BWGL

F         ACS

GB      WRAS

USA    FDA conformity in accordance with CFR 21 §177.2600 and 3-A Sanitary


✓ Applications: hot water

✓ Hardness range: 60 to 88 Shore A

✓ Can be processed in compression, transfer and injection molding processes

✓ EN 16421, WRAS und ACS approval

✓ Suitable for use in accordance with the KTW-BWGL applicable as of 03/01/2025

✓ Type test in accordance with the KTWL-BWGL (Classification P2)


D         EN 16421

Suitable for type test in accordance with the KTW-BWGL

F            ACS

GB        WRAS

KRAIBURG Pure - Certified compounds. For the future.

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Why use rubber compounds, especially EPDM, for drinking water applications?

To ensure safety and quality in industrial and chemical process environments, manufacturers worldwide count on our extensive experience with solutions for the water and gas industry.

The quality of drinking water is subject to strict legal regulations. Water treatment plant and system operators have a responsibility to ensure supply of drinking water to the population and to comply with the legal framework. Varying quality of raw water and protection of water resources from contamination are constantly presenting them with new challenges.

Good reasons why drinking water systems should be based on good solutions. Valves, flow meters, pumps and other equipment often contain rubber seals, fittings as well as diaphragms. Because of their important function, you should opt for high quality in the rubber components included in your product.

Overview of approvals

Approval according to DIN EN 16421

Plastics and other organic materials that encounter drinking water (including elastomers) must fulfill hygienic requirements. The KTW-BWGL (Evaluation criteria document for plastics and other organic materials) of the German Federal Environment Agency specifies criteria according to which the materials must be evaluated.

To demonstrate conformity of drinking water hygienic suitability, an additional test procedure is required to determine the multiplication of microorganisms. For this purpose, the promotion of microbial growth by the materials in contact with drinking water is investigated according to the specifications of the DIN EN 16 421 (formerly: DVGW W 270) standards.

If the materials and substances meet all these requirements, they comply with the Federal Environment Agency’s assessment criteria for plastics and other organic materials in contact with drinking water and can guarantee impeccable drinking water quality in the products used.

ACS approval

The sulphur cross-linked elastomer compounds, which only contain raw materials which are permitted to be used after 2021, now also have the French drinking water certification ACS (Attestation de conformité sanitaire). The ACS system was developed in 1999 by the French Directorate-General for Health (Direction Général de la Santé).

The certification, which has been mandatory since 2006, confirms the suitability of products which encounter drinking water, and which are suitable for human consumption.

WRAS approval

In addition, KRAIBURG Pure compounds hold the British drinking water approval WRAS (Water Regulations Advisory Scheme). Here, the British water regulations authority lays down requirements to check materials for their effect on the water quality. This based on the British standard BS6920:2000.

Approval process

In the first stage, the materials used to make the product are examined for effects on the organoleptic (taste, appearance, smell, color) and chemical properties of drinking water. In further tests, these are evaluated regarding their cytotoxic reaction and the stimulation of microbial growth to prevent drinking water contamination. If all requirements stipulated in WRAS are met, approvals are granted.

FDA conformity

FDA conformity confirms the suitability of materials for use in foodstuffs in accordance with the regulations of the U.S. Food and Drug Administration (FDA), whose main task is to protect the public health of the United States. Verification of the conformity is obtained by checking the permitted recipe components and the migration requirements on the finished part.

The test plates made from KRAIBURG Pure have successfully passed these migration tests and are thus suitable for finished parts that require a positive FDA approval.

3A Sanitary Standards

As well as the European approvals, KRAIBURG Pure compound series also meets the requirements in accordance with 3A Sanitary Standards. The American organization of the same name stipulates hygiene standards for machinery and systems which are used in the dairy, food, drink, and pharmaceutical industries.

Among other things, these standards include requirements of the material suitability and fitness for purpose of rubber and materials like rubber, for example, compatibility with cleaning agents and disinfectants which are integrated into the machinery and systems, and which encounter the product.

One main requirement of 3A Sanitary Standards states compliance with the FDA regulations in accordance with CFR 21 Section 177.2600, which determine the permitted “ingredients” of rubber which is to be used in the food industry.