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The Family of Standards

We explain here the respective roles of WIS & IGN relative to British (BS), European (EN) and International (ISO) Standards & when they can, or cannot, co-exist.

European Standards (EN)

Under the Utilities Directive, which came into force on 31 January 2006, where a European Standard (EN) covering the proposed product exists, this must be used in the purchasing and therefore, to meet market demand, in the manufacture of the product.

Post Brexit, approximately 3,500 European standards, adopted as British Standards, continue to confer a ‘presumption of conformity’ to product regulation in the UK under the UKCA marking regime.

The European Standards Store (offsite link to is a useful first point of enquiry.

British Standards (BS)

If an EN does not exist, national standards from EU member states should be sought (i.e. a BS in the UK). This still applies post-Brexit.

There are approximately 33,000 current BS or some 63,000 including those in draft. Many will apply in some context to water industry activities.

The BSI shop (offsite link) is a useful first point of enquiry.

Water Industry Specifications (WIS)

European and national standards will not normally be available in the case of newly developed products, but this is not to be seen as inhibiting the use of such products. To fill this gap, a series of tailor-made specifications (WIS) is produced by the Water Industry. WIS must not conflict with a BS or EN once these are published. At that point they should be withdrawn or modified to avoid such conflict.

Information and Guidance Notes (IGN)

In addition to the need for technical specifications covering performance, testing and quality control procedures, there are occasions when the water industry as a whole wishes to provide guidance to the individual water and sewerage suppliers and their suppliers. Information and Guidance Notes (IGN) have been developed for this purpose. An IGN can complement a WIS, BS or EN but must not conflict with any of them.

International Standards (ISO)

The International Standards Organisation (ISO) is an independent, non-governmental international organization with a membership of 165 national standards bodies. The European Committee for Standardisation (CEN) is a regional body of ISO within that context.

ISO has developed over 24125 International Standards and all are included in the ISO Standards catalogue ISO – TC (offsite link). Adoption of an ISO standard is voluntary – although one out of three European standards is now identical with an ISO publication.

Cooperation and precedence in standards development between ISO & CEN is governed by the Vienna Agreement (offsite link).