Traditional materials retain a large share of the market for water, sanitary and waste services products, as indicated in earlier chapters, but the newer plastics materials are now well established in many applications. Extensive information is available in British Standards published in the past 20 years or so, arising in many aspects out of parallel work under the aegis of the International Organization for Standardization (ISO). This is contributing to the development of CEN standards. The following notes, which draw on such information, are intended as an introduction to some of the plastics used. For further reading, apart from the many standards and regulations, publications of the Institute of Materials contain much research and development information. Practical aspects are dealt with in the Institute of Plumbing's Plumbing Engineering Services Design Guide. BRE Digest 382 (1993) deals with new materials used in hot climates. Potential for development is discussed by Staniforth (1994).