Skip to main content

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 meters and many others. It also covers non-metallic products such as rubbers, coatings, cements, resins and sealants.

Click here to learn more

Ready To Begin the Process?

Contact us with questions or to receive a quote.

What’s New with NSF

  • NSF Launches Independent Certification Standard for Compact Products

    August 25, 2026
    New third-party certification verifies products cutting materials and shipping impacts while maintaining safety and performance.
    Read the Story
  • CELSIUS® Products Earn NSF Certified for Sport® Certification

    August 20, 2026
    CELSIUS® has earned NSF Certified for Sport® certification for select products, including the CELSIUS VIBES line, reinforcing the brand’s commitment to quality, transparency and consumer trust.
    Read the Story
  • Thomas Vyles Honored With 2026 Walter F. Snyder Environmental Health Award

    August 19, 2026
    The award honors Walter F. Snyder, co-founder and first executive director of NSF, and pioneers whose work advances environmental and public health.
    Read the Story
  • NSF Hosts First External Review Panel for ‘NSF/KWTC 555’ with Key Asian Water Authorities

    August 3, 2026
    Joint standard development gains momentum to enhance confidence in Asia’s water industry and advance drinking water safety.
    Read the Story