EU Drinking Water Directive: How the rubber industry must adapt by 2027

The revised EU Drinking Water Directive (DWD) will enforce strict new rules on elastomer seals, gaskets, and other components that come into contact with drinking water starting January 1, 2027. Samantha Duffy, Senior Manager of Global Water Programs at NSF, outlines the sweeping changes and their implications for the rubber industry. The directive’s framework is now finalized, with six legal acts—three Implementing Decisions and three Delegated Regulations—adopted in January 2024 and published in April 2024. These measures apply from 2027, leaving no room for individual derogations or late revisions. The only flexibility lies in the ‘positive lists’ of approved substances, which are dynamic and subject to periodic review. Economic operators can now notify the European Chemicals Agency (ECHA) of their intent to support a substance, with applications for additions, amendments, or maintenance open from December 31. Each entry on the positive list carries an expiry date—2028, 2031, 2034, or 2037—and failure to apply for renewal results in removal. Duffy emphasizes that companies must plan for the 2027 deadline, as waiting for exemptions is not a viable strategy. For rubber manufacturers, the directive introduces three major shifts. First, formulation transparency is now mandatory: every starting substance in a compound—including base polymers, cure systems, activators, antidegradants, plasticizers, process aids, and fillers—must trace back to an entry on the EU positive list. Unlisted substances require justification or additional testing. Second, testing protocols have expanded significantly. Products must undergo migration tests under cold, warm, or hot conditions, GC-MS screening for unexpected substances (including reaction and degradation by-products), total organic carbon analysis, and assessments for odor, flavor, color, turbidity, and microbial growth. Third, conformity assessment now requires EU type examination, annual site inspections, an EU Declaration of Conformity, and mandatory ‘Suitable for Drinking Water’ marking. This affects compounders, component manufacturers, raw material suppliers, and OEMs across the supply chain. Companies that fail to comply face stark consequences. Those holding a valid national certificate (such as a UBA listing or ACS attestation) by December 31, 2026, can continue selling their products under that scheme until the end of 2032—but only in the country that issued the certificate. Any changes to composition or performance invalidate the approval, and national certifications do not grant access to the broader EU market. Companies without a national certificate have no transitional protection: from January 1, 2027, compliance with EU Minimum Hygiene Requirements (EU-MHR) is mandatory for market access. The commercial deadline is effectively earlier, as OEMs and utilities are already incorporating EU-MHR conformity into their post-2026 procurement specifications. The directive’s impact will vary by material and application. Heavily compounded elastomers, such as EPDM or NBR, face the greatest scrutiny due to their complex formulations, where every ingredient must align with the positive list. Simpler chemistries have less exposure. Wetted surface applications are classified by surface area, contact time, and function, with hoses, flexible connectors, expansion membranes, and diaphragms facing the most stringent testing. Static seals and O-rings typically fall into lower-risk categories, but assemblies must comply based on their highest-risk component, meaning a single non-compliant seal could drag an entire valve or meter into stricter testing. Member States’ preparedness varies, with some already aligning with the directive’s requirements while others lag behind, creating a fragmented landscape for industry compliance.