The NSF REG4 Certification for the UK Helps Plumbing Products Show Compliance
The NSF REG4 certification scheme for the UK market allows plumbing products and materials to show compliance with the Water Supply (Water Fittings) Regulations 1999.

NSF REG4 Certification & The Regulators’ Specifications
All manufacturers selling water supply products into the UK must meet Regulation 4, a section in these regulations:
- Water Supply (Water Fittings) Regulations 1999
- The Water Supply (Water Fittings) (Scotland) Byelaws 2014
- The Water Supply (Water Fittings) Regulations (Northern Ireland) 2009.
NSF RG4 is your solution to meet the Regulators’ Specifications.
The scope of this certification scheme includes mechanical products in contact with drinking water, such as valves, backflow prevention devices, taps, mixers, shower heads, pipes and fittings, tanks, cisterns, water metres and many others. It also covers non-metallic products such as rubbers, coatings, cements, resins and sealants.
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What’s New with NSF

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NSF Achieves European Accreditation for Drinking Water Product Certification Ahead of 2027 EU Deadline
July 22, 2026The ISO/IEC 17065 accreditation from BELAC complements NSF’s testing capacity, enabling end-to-end support for EU Drinking Water Directive (DWD) readiness ahead of the January 2027 deadline.
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July 15, 2026NSF is excited to be exhibiting at Fruit Attraction, a leading international trade fair for the fruit and vegetable sector.