KIWA, WRAS and NSF - what are the differences?

Two years on from REHAU’s change over to a KIWA UK reg4 certification there are still many common misconceptions for drinking water approval.

14.11.2024

Demystifying drinking water approval

Across the UK, any products used inside buildings and connected to the water supply must comply with The Water Supply (Water Fittings) Regulations. In the past the most common method of demonstrating compliance was to obtain WRAS approval, but today equivalent independent certification is also offered by KIWA and NSF.

Often, we find our customers seeking reassurance of product compliance and requesting WRAS certification. While WRAS Approval remains widely recognised, equivalent certifications from KIWA and NSF can offer the same and sometimes higher levels of assurance.

KIWA and NSF, like WRAS, offer validation for regulation compliance for manufacturers and distributors of plumbing products in line with the regulation requirements. The product testing and certification guarantees that a product is safe, for the consumer, to be used in contact with drinking water.

The different certification levels

There are different certification levels available to manufactures. Level 3 is most similar to past WRAS approvals with initial testing and only a full re-test every 5 years. Here at REHAU, we have decided to go further than with WRAS and opted for Level +1 with KIWA, which involves everything Level 3 does plus an initial factory audit, followed by annual factory audits.

What is tested?

There are multiple key testing areas, all accessing the safety, performance and durability to not only comply with The Water Supply (Water Fittings) Regulations, but also the product performance, reliability and safety.

The key testing areas are on the impact on water quality (BS 6920) and on Mechanical and Functional Testing to relevant BS standards and long-standing test code sheets from the Drinking Water Inspectorate (DWI/DEFRA).

How do I know if a product is KIWA certified?

It is important to ensure any product being installed has the correct approval. The most reliable way to check if a product is certified, is to check the KUKreg4 Approved Products List database online, which lists all water regulation approved products.