The Regulations:

The following regulations apply to the approval of substances and products used in the provision of public water supplies within the United Kingdom:

England – regulation 31 of The Water Supply (Water Quality) Regulations 2016 (as amended) (Statutory Instruments 2016 No 614) (

Wales – regulation 31 of The Water Supply (Water Quality) Regulations 2018 (Welsh Statutory Instrument 2018 No 647 (W.121) (

Scotland – regulation 33 of The Public Water Supplies (Scotland) Regulations 2014 (

Northern Ireland – regulation 30 of The Water Supply (Water Quality) Regulations (Northern Ireland) 2017 (Northern Ireland Statutory Rules 2017 No.212) (

Where reference is required to specific regulatory requirements, these are given in footnotes.

The Authorities

Under the relevant regulations water suppliers shall not apply or introduce any substance or product into public water supplies unless the requirements of the relevant regulations are met. One of these requirements is that the substance or product has been approved by either the Secretary of State for the Environment Food and Rural Affairs (England), the Welsh Ministers (Wales), the Northern Ireland Assembly (Northern Ireland) or the Scottish Ministers (Scotland); collectively referred to as “the Authorities”.

The List

Under the relevant regulations lists of all the substances and products approved or refused, and of all approvals revoked or modified are published at least once a year:

England and Wales: this list is regularly updated by DWI throughout the year, and includes details of changes to approved products and additions to the List. The List (the List of Products for use in Public Water supply in the United Kingdom) is posted on the DWI website . Reference to “the List” throughout this publication refers to the most up-to-date version available from the website.

Scotland: refer to the List produced for England and Wales on their own website at Approved Products and Processes for use in the Public Water Supply | DWQR

Northern Ireland: in due course the Department for Regional Development (Northern Ireland) will also publish a list.

The Approval of a Product

Approval is based upon consideration as to whether the use of a substance or product will adversely affect the quality of the water supplied, or cause a risk to the health of consumers; no consideration is given to fitness for purpose and approval by the Authorities must not be taken as a favourable assessment of the performance or merits of any substance or product. It is the responsibility of the end user to ensure fitness for purpose.

The approval process for general products used with water intended for human consumption is set out in Advice Sheet 1 . Relevant deviations from this process are set out in the appropriate Advice Sheets.

Water Suppliers

These include water undertakers, inset appointees, and water supply licensees; see The Water Act 2014.

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