Version 8.5, April 2023
This Advice Sheet covers the requirements for applications for approved products using recognised materials, as well as the requirements to submit an application for a recognised material to be added to the list of recognised materials found in Annex 3 of the List of Approved Products.
The Authorities do not approve individual materials only products that will be supplied directly to drinking water suppliers for use in contact with water intended for human consumption.
However, particular grades of materials for use in the:
- extrusion of pipes;
- factory coating of products; and
- fabrication of products
have been assessed for their effects on drinking water quality. These materials, known as recognised grades, can be used to manufacture products without the need to provide full formulation details or to carry out full testing. Recognised grades have not been approved by the Authorities and cannot be used in contact with drinking water by water companies unless as part of an approved product. Recognised grades of these materials are listed in Annex 3 of the List.
An application is required for both products seeking approval that are constructed from a recognised grade of material as listed in Annex 3, as well as a material seeking to be listed in Annex 3 for a product manufactures use.
2. Plastic Pipes
The following requirements apply to pipes made from the previously assessed and recognised grades of plastics and outlined in Figure 1:
- The application must be made by the supplier of pipes to the water industry on the Pipes Systems Application Form. Full disclosure of the formulation of the recognised grade is not required.
- The applicant must provide an “Instructions for Use” document for its pipe. Guidance on producing this document is given in Advice Sheet 2.
- The applicant must provide a copy of an odour and flavour test (BS 6920-2.2.2 or equivalent European test) carried out on test samples, taken at random from three different production batches of the smallest diameter pipe for which approval is sought. Each test must have been undertaken by filling test lengths of pipe incorporating appropriate heat weld or solvent weld joints (as outlined in the IFU).
- That the recognised grade remains valid in Annex 3 of the List, i.e. is within the listed expiry date.
Applications should be made in the normal way as described in Advice Sheet 1 where a plastic material is not intended to be added as a recognised grade.
2.3 Applications to add a New Grade of Plastic to the Recognised Grades List
This may be undertaken in two ways as outlined in Figure 2, either:
- A plastic grade manufacturer may make an application, similar to the product application process. Currently there isn’t a recognised grades application form on the Reg31 portal. Please contact the Reg31 team for instructions on making an application Reg31.Enquiries@defra.gov.uk. Any testing requirements would be on extruded pipe test pieces and required to be assessed prior to inclusion to Annex 3.
- A pipe manufacturer may obtain approval for a pipe made from a grade of plastic not on the recognised grades list using the normal product approval process, after successful approval and with the agreement of both the pipe and material manufacturer, the grade may be added to the recognised grades list in Annex 3. These types of application are often carried out in collaboration.
Figure 1. Details the application process for products manufactured from recognised materials.
Figure 2. Details the application process for products manufactured from non-recognised materials or application of material recognition.
3. Factory Applied Coating
3.1 Application for a product using a Coating from the Recognised Grade List
Products incorporating factory applied coatings are subject to the requirements of Regulation 31. Many items with a factory applied coating are small surface area (see Advice Sheet 8); for those that are not small surface area approval of the final product is required. Products incorporating coatings which are listed in Annex 3 of the List of Approved Products can be approved after limited testing. Products which have coatings which are not on the List will require full testing for either a product approval or for addition to the list of recognised materials.
Applicants for products using recognised coatings should submit the Site and In-Situ Applied Coatings application form through the Reg31 portal, but do not require a full formulation declaration or full testing. The application should:
- note the coating being used and confirm that it is being applied in accordance with the coating manufactures IFU for that coating;
- provide an Instructions for Use document for the product; and
- The applicant must provide a copy of an odour and flavour test (BS 6920-2.2.2 or equivalent European test) carried out on test samples, taken at random from three different production batches of coated product for which approval is sought.
- Repair requirements for the water company that comply to the coating manufacturers material repairs to be included in the coated product IFU.
This may be undertaken in two ways as outlined in Figure 2 above, either:
- The coating manufacturer may make an application using a recognised material grade application form, similar to the product application process. Any testing requirements would be on coated test pieces and required to be assess prior to inclusion to Annex 3.
- A product manufacturer may obtain approval for a product coated with a coating not on the recognised grades list using the normal product approval process. If the test results are suitable (e.g. there are no other materials present in the product and the surface to volume ratio of the tested piece was suitable) then, with the agreement of both the product and material manufacturer, the coating may be added to the recognised grades list in Annex 3.
- The coating manufacturer must provide details of the repair requirements for the coating for the factory coating process and for the installation at site (these details may be the same). The repair at installation will be included in the approved product IFU. Additionally, the coating manufacturer will provide details of the maximum free chlorine levels permissible for contact with the final coated product, again for inclusion in the approved product IFU.
- Currently there isn’t a recognised grades application form on the Reg31 portal. Please contact the Reg31 team for instructions on making an application Reg31.Enquiries@defra.gov.uk.
4. Stainless Steel
All stainless steel products used in contact with water for public supply must be approved under the relevant regulations, unless considered to be a low-risk product; see Advice Sheet 8.
A number of grades of stainless steel specifications have been tested by The British Stainless Steel Association and had been accepted as recognised grades, these referenced mainly “304 or 316” grades. However, BSEN 10088 provides lists of suitable grades of stainless steel and is maintained as a living document and updated with additional appropriate grades. Within this are grades suitable for drinking water use. Generally, Austenitic grades have been referenced as containing minimum suitability for use with drinking water, with grades “304 and 316” falling within this category. The applications should provide the reference to the grade and suitability for use with drinking water. The other categories of stainless steel that demonstrate suitability can be found in the BSSA operational guidance.
The fabrication method can potentially affect the stainless steel and all stainless steel items must be manufactured in accordance with The British Stainless Steel Association’s Operational Guidance and Code of Practice, available from the BSSA Website.
Fabricators can apply for approval of their products made from stainless steel. The application should be made on the Stainless Steel Construction Products application form, on the Reg31 portal and include an undertaking that all products manufactured for use in contact with drinking water for water company installations will be made from suitable grades and in accordance with The British Stainless Steel Association’s Operational Guidance and Code of Practice. If DWI is satisfied with the evidence provided, it will recommend approval of the product (or range of products).
Products fabricated by manufacturers on the lists are approved provided they comply with the following conditions. Products must be:
- made from stainless steel materials on the list BSEN 10088 stainless steels;
- fabricated in accordance with Operational Guidance and Code of Practice for Stainless Steel Products in Drinking Water Supply, published by the British Stainless Steel Association;
- use other water contact materials (seals, gaskets etc.) in accordance with regulation 311 (either 31(4)(a) or 31(4)(b)). These should be agreed with the water company at the point of specification; and
- supplied with documentation to the water company, for their records, to confirm which items supplied are covered by the approval.
Stainless steel communication pipes can be used under regulation 31(4)(b) provided the product meets the requirements in Advice Sheet 8 and would not require regulation 31(4)(a) approval so long as:
- the pipe is made from grades of stainless steel as detailed BSEN 10088 as unlikely to cause a problem in contact with water, and
- drinking water suppliers adhere to “Operational Guidance and Code of Practice for Stainless Steel Products in Drinking Water Supply”, published by the British Stainless Steel Association.
5. Other Metallic Products (Including Metallic Coatings)
- The copper pipes conforming to BS EN 1057 “Copper and copper alloys. Seamless, round copper tubes for water and gas in sanitary and heating applications”; and
- The pipe is installed in accordance with the relevant sections of “Copper Tube in Domestic Water Services: Design and Installation” published by the Copper Development Association.
Unrestricted use of galvanised steel pipes is not permitted. However, galvanised steel may be suitable for use in certain water compositions. Any supplier seeking to install galvanised steel for use in public water supplies should make an application to DWI for approval following the recommendations in section III of the 4MSI metal composition document – see link below.
Fittings and ancillaries with small surface areas are not exempt from approval requirements under the relevant regulations. the suitability for the category of use can be found in the 4MSI metallic compositions document – see link below.
Products which do not fall into the category of small surface area as defined in Advice Sheet 8 will normally fall under the full requirements of the relevant regulations. Such products are considered, on a case-by-case basis, by the DWI utilising the positive list updated by the 4MS Initiative “Acceptance of metallic materials used for products in contact with drinking water” and select “Common Approach on Metallic Materials – Part B: Positive list of compositions”.
regulation 31 of the Water Supply (Water Quality) Regulations 2018 in Wales, regulation 33 of the Water Supply (Water Quality)(Scotland) Regulations 2014, and regulation 30 of the Water Supply (Water Quality Regulations) (Northern Ireland) 2017 ↑