Notes on Sections of the List
Part A: Chemicals and Filter Media
It is the responsibility of the drinking water suppliers to ensure that
(a) the method and manner of use; and
(b) the purity of these chemicals and products are such that the water treated meets the requirements of the relevant regulations. Where appropriate, additional specific conditions of approval are listed against the chemical or product.
Approval holders and water companies should be aware that products or substances that claim to have a biocidal effect or are used as biocides may require authorisation under the Biocidal Products Regulation. HSE is the UK competent authority for the Biocidal Products Regulation and so any queries about whether that legislation applies to a specific product or substance should be addressed to biocidesenquiries@hse.gov.uk
A.5: Disinfection or cleaning agents of membranes
During the approval process there is no evaluation of a product’s effectiveness, only of its safety in use. An approval given in this section does not certify that the Authorities are satisfied that that the product is effective, but only that it is safe for use in accordance with the Instructions for Use supplied. The fact that a product is approved does not justify any claim about its effectiveness.
A.6: Disinfectants for emergency use
Disinfectants for emergency use are no longer approved and listed under the requirements of relevant regulations. Guidance upon the choice and use of disinfectants in an emergency is provided in Advice Sheet 9
Approvals of previously listed disinfectants for emergency use have been revoked.
A.7.2: On-site electrolytic generation of chlorine
Products in this section are not fully covered by EN 901 (sodium hypochlorite) and must conform to the following conditions of use:
(i) the method of use and the purity of the output of these products shall be such that, in the case of water for public supply, the water so treated meets the requirements of the relevant Regulations; and
(ii) the treated water must not contain more than 700 µg/l chlorate.
A.7.3: On-site generation of chlorine dioxide
Products in this section are not fully covered by EN 12671 (chlorine dioxide). The following products must conform to the following conditions of use:
(i) the method of use and the purity of the output of these products shall be such that, in the case of water for public supply, the water so treated meets the requirements of the relevant Regulations; and
(ii) the combined concentration of chlorine dioxide, chlorite and chlorate shall not exceed 0.5 mg/l as chlorine dioxide in the water entering supply.
Part B: Products for the conveyance of water
B.1.3: Polyvinylchloride (PVC) pipes
Please note that all approved PVC pipes are made with on-lead stabilisers.
B.1.7: Cement mortar lined pipes
For Products in this section, the following conditions applies:
Before connection to the supply, the water undertaker or their appointed agent, must carry out tests to establish that migration from the cement mortar lining will not cause a contravention of the upper prescribed concentration for hydrogen ion in the relevant Regulations.
B.3: Products for conveyance of water (Emergency use)
For products in this section the following condition applies:
These products are primarily intended for emergency use and are approved for limited use only and may not be permanently installed in, or used in conjunction with any system for treating or distributing public water supplies. If the proposed use will extend beyond a 90 day period of use on any one occasion, then advice from the DWI should be sought before installation and use.
NOTE: some of these products may be suitable for limited use during planned maintenance. In this case it is the responsibility of the water supplier to undertake a thorough risk assessment of the proposed use, including fitness-for-purpose and why other products, already fully approved under the relevant regulations cannot be used. Use of any of these products during planned maintenance shall be in accordance with the condition set out above.
Part C: Lining, coatings, sealant and repair materials
C.2: In-situ applied pipe coatings
In-situ applied lining products approved for use by the Authorities for the relining of existing water mains/pipes must be applied in accordance with strict operational requirements as documented in the Water Industry Information & Guidance Note IGN 4-02-02 “Code of Practice: In-situ resin lining of water mains” and the Water Industry Specification WIS 4-02-01 “Operational Requirements: In situ resin lining of water mains”.
The coatings listed in this section have been subject to review by DWI (including testing), on the basis of their proposed use with inert substrates such as metallic or cement based structures (or as specified in the manufacturer’s Instructions for Use (IFU)), and upon the detailed application and curing requirements set out in the IFU. They have not been evaluated for any other aspect, such as fitness for purpose.
For use with other non-metallic non-cementitious materials, such as plastics, other coatings/linings, and rubbers, a specific application for approval would be required for use of the coating with a specific substrate.
C.2.1: Coatings based on epoxy resins
These products must be applied by a certified contractor.
C.2.2: Coatings based on polyurethane
These products must be applied by a certified contractor.
C.2.3: Coatings for small diameter pipes
This section covers pipes up to 75 mm internal diameter. The products listed in this section shall be applied by certified contractors in accordance with strict operational requirements as documented in the Water Industry Specification WIS 4-02-03 “Operational Requirements : In-situ polymeric lining of service pipes”.
C.3: Site applied coatings for water retaining structures
The products listed in this section, in addition to being approved for site applied coatings for water retaining structures, are suitable for use in large diameter mains where they can be applied by hand e.g. brush or spray.
The coatings listed in this section have been subject to review by DWI (including testing), on the basis of their proposed use with inert substrates such as metallic or cement based structures (or as specified in the manufacturer’s Instructions for Use (IFU)), and upon the detailed application and curing requirements set out in the IFU. They have not been evaluated for any other aspect, such as fitness for purpose.
For use with other non-metallic non-cementitious materials, such as plastics, other coatings/linings, and rubbers, a specific application for approval would be required for use of the coating with a specific substrate.
C.3.1: Coatings based on epoxy resins
The following conditions apply unless otherwise indicated:
(i) the minimum cure time is 16 hours; and
(ii) the minimum cure temperature is 3°C.
C.4: Flexible covers and linings for water retaining structures
Note: Laminated flexible covers and linings for water retaining structures may not necessarily have been assessed for uses totally immersed in water, e.g. as baffles. For information on use see individual product Instructions for Use (IFU) document.
Part D: Membrane and filtration systems
For products in this section the following general condition applies:
Products must be installed upstream of any final point of disinfection.
Part E: Other water treatment works installations
There are currently no notes under this section.