Freudenberg seals safer drinking water supply

Weinheim, Germany – Freudenberg Sealing Technologies (FST) has developed a new EPDM compound for O-rings, which is designed to meet stringent drinking water application requirements, ensuring protection for both health and the environment.

O-rings manufactured from the 70 EPDM 335DW materials have obtained all relevant market approvals for, making them suitable for global drinking water use, said an announcement from the global sealing products manufacturer.

According to a 2024 report by UNESCO, 2.2 billion people worldwide live without access to clean drinking water and 3.5 billion lack access to safely managed sanitation, according to the FST release issued 19 March.

This, it said, is where solutions like the O-ring made from the EPDM compound are needed, as it “ensures a long service life and reliable sealing function.”

In particular, FST pointed to the ability of the material to withstand temperatures up to +150°C, while remaining effective down to -50°C (static).

Additionally, an external O-ring research laboratory has tested for copper compatibility and did not find any copper-induced autoxidation, the German-based manufacturer further pointed out

“The compound demonstrates good aging resistance and is suitable for drinking and process water, hot water, superheated steam, silicone oils," said Klaus Schmieder, segment manager at FST.

These characteristics, he added, make the EPDM grade especially suitable for clean drinking water applications, where durability and safety are paramount.

Highlighting a range of certifications*, FST said the new O-ring material is “not only certified to current evaluation criteria for plastics and other organic materials in contact with drinking water (KTW-BWGL).

"For the first time, uniform requirements will be set for materials in contact with drinking water and the approval will be recognized within the various independent testing institutes within the EU.”

The EPDM, it added, has also been tested regarding the currently available European Positive List: the composition meeting the requirements of EU Directive 2020/2184 and recognised by independent testing institutes across the EU.

"The rigorous testing and compliance with international standards demonstrate our commitment to providing high-quality materials that protect public health and meet the demands of modern drinking water systems," concluded Schmieder. 

*O-Rings made of 70 EPDM 335DW are tested and certified according to norms like KTW-BWGL, DIN EN 681-1, ÖNORM B5014, EN 16421, CE1935/2004, WRAS BS6920, AS/NZS 4020, FDA §177.2600, KIWA BRL-K17504 and NSF/ANSI 61. Applications requiring ACS certification (Attestation de Conformité Sanitaire) are currently covered by a CLP (Classification, Labelling and Packaging) certificate valid for O-rings smaller than 63 mm. The full ACS certification for larger O-rings is currently being tested.

Image: © Freudenberg Sealing Technologies 2025