Hexpol (Malmö / Sweden; www.hexpol.com) has developed "Dryflex DW", a special range of thermoplastic elastomers (TPE) designed for applications that come into contact, either directly or indirectly, with drinking water.

This can include domestic and commercial applications, such as plumbing seals, pipe fittings and shower-heads. Hexpol said that Dryflex DW TPEs had passed the German drinking water regulations KTW as well as received W270 approval.

Key properties for the material, which can be injection moulded or extruded, include being tested and approved for W270 and KTW guidelines for cold and warm water (23 °C / 60 °C), raw materials compliant with food contact regulation (EU) No 10/2011 and a hardness range from 50 to 90 Shore A. The material is available in natural and black as well as custom colours with compliance certification, and it shows no microbial growth according to W270, without the use of biocides.

Dryflex DW TPE compounds have also been tested and approved according to "The Guideline for Hygienic Assessment of Organic Materials in Contact with Drinking Water," and approved according to DVGW Technical Standard W270, which describes a test method to determine microbial growth on non-metallic materials intended for use in drinking water systems.