Report No DWI0722

IMPROVED MATERIAL TESTING PROCEDURES

Final Report to the Department of Environment

DWI0722

Jun 1995

EXECUTIVE SUMMARY

The Drinking Water Inspectorate operates on behalf of the Secretary of State for the Environment and the Secretary of State for Wales a statutory approval scheme for materials used in contact with water supplies and chemicals used in water treatment. A number of EU and other countries operate approval schemes which differ in a number of aspects from the UK scheme and from each other. This means that suppliers often need to submit their products to similar testing and approval procedures in each country in which they wish to sell their products.

The Construction Products Directive (89/106/EEC) (CPD) was introduced to ensure an open market. It specifies that water supply products must satisfy Essential Requirements (ER), including a requirement for no adverse effect on the quality of water supplies. The European Committee for Standardisation (CEN) is drafting standards for testing to demonstrate compliance with the ER. The ER apply to construction works and not to its individual components. The product standards for components are required to ensure that the finished works will meet the ER. The intention is that the European standards will, eventually, replace national standards.

This contract was established in September 1990 to provide information on current approval schemes in other countries and on the developments within CEN, and to provide experimental data and technical advice to enable the adoption of the most appropriate UK and CEN test procedures and approval schemes.

The major approval schemes for materials used in contact with drinking water operated in Europe and the USA have been assessed and an Inventory of European Approval Systems has been published.

WRc has provided technical advice on the drafting of CEN standards for testing the effects of materials on drinking water including participation in drafting meetings and preparation of discussion documents.

WRc also participated in two interlaboratory studies organised by CEN, i.e. an extensive validation study on a leaching test procedure for factory-made products (TC164/WG3/AHG2), and a smaller study on the determination of acrylamide monomer in polyacrylamides (TC164/WG9/TG8).

For products which are applied on site, the available data from laboratory and field leaching tests has been collated and additional laboratory studies have been performed to assess the effects of various test conditions on the results. Dynamic tests on in situ lined pipes under controlled conditions have been proposed to provide realistic and reliable information.

Copies of this report may be available as an Acrobat pdf download under the 'Pre 2000 Reports' heading on the DWI website.