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Doc M Bathrooms: Everything You Need to Know About Regulation 4

When designing or specifying accessible toilets and bathrooms, Approved Document M isn’t the only legislation you’ll have to bear in mind.

Water appliances like taps and showers for disabled bathrooms fall under the banner of ‘Reg 4’, and NYMAS Group offers a range of products to fulfil and comply with this legislation.

But what exactly is Reg 4? Who administers compliance for it – and how can you make sure the products you select for your accessible projects meet the required standards? Let’s take a closer look at the ins and outs of Reg 4.

What is Reg 4?

Regulation 4 is a part of the Water Supply (Water Fittings) Regulations 1999, designed to ensure that water fittings are of an appropriate quality and standard for installation.

Reg 4 sets out the legal requirements for the design, installation, operation and maintenance of plumbing systems, fitting and water using appliances with the focus on preventing misuse, waste, undue consumption and most importantly, water contamination (drinking water).

Reg 4 compliance means ensuring that mechanical products with drinking water contact such as valves, backflow prevention devices, taps, mixers, shower heads, pipes and fittings, tanks, cisterns, water meters, and all component parts of these are fit for purpose and that none of the materials used to manufacture a water fitting – for example metals or plastics – are capable of leaching into the water supply. Non-metallic materials that contact water are also required to comply with BS 6920.

NYMAS Group taps and other water appliances are designed and manufactured to comply with Regulation 4. To certify whether products comply, testing bodies are required to ensure this responsibility is met.

TMV3 Thermostatic Mixer Valve


What are the requirements of Reg 4?

Reg 4 applies in all premises where water is supplied by a water company, from the point that the water enters the property to the water being used through a plumbing system or water appliance. The primary requirement is to ensure that all water fittings are of an appropriate quality and standard. As such, fittings must:

  • Conform to an appropriate British Standard
  • Conform to a specification approved by the regulators

In addition to this, the water appliances being supplied must be considered in a wider context, including:

  • Compatibility with other water fittings in a plumbing system, and system operational parameters (e.g. water temperature, pressure and flow).
  • Location-specific parameters such as the environment (for instance, if there is a risk of frost or corrosion) backflow risks, and product installation requirements or constraints.

Regulation 4 also requires that water fittings are installed by competent persons who are familiar with the regulations and standards related to water supply and plumbing.


What appliances are regulated by Reg 4?

A large variety of water appliances incorporate Regulation 4. When we think of Reg 4 we typically think of taps and shower assemblies – but all the components and materials used in these are also required to be certified. This includes plastics, rubbers, coatings, cements, resins and sealants.

When you choose water appliances from NYMAS Group, you can rest assured that every aspect of our products has been tested to ensure full and complete compliance with the standards set out by Reg 4.

Where does Reg 4 apply?

Regulation 4 of the Water Supply (Water Fittings) Regulations 1999 applies in England and Wales. Similar regulations exist in Scotland and Northern Ireland under their respective legal frameworks. These regulations are designed to achieve similar objectives, but they may have variations in their requirements and enforcement mechanisms.

If you are outside of the UK or require specific information about similar regulations in Scotland or Northern Ireland, you should refer to the relevant water supply regulations applicable in those regions.

Responsibility for Reg 4 compliance comes down to all users, owners or occupiers and anyone who is installing plumbing equipment, water fittings and appliances.


Who administers Reg 4 compliance?

In relation to washroom accessories or water fittings, you may notice the terms ‘WRAS/ KIWA /NSF Compliant’ being used to describe Reg 4 products. These are certified independent bodies that specialize in testing and assessing water fittings to make sure they comply with Regulation 4, which is the minimum legal requirement.

Until more recently, WRAS approval was the most common method of demonstrating Regulation 4 compliance. However, KIWA and NSF now also offer certifications independently. Additionally, KIWA, like WRAS, has a widely accepted KUKreg4 (KIWA UK Regulation 4) approval mark which demonstrates full compliance with the UK Water Supply (Water Fittings) Regulations 1999. Here’s an overview of the main certifying bodies:

Water Regulations Approval Scheme (WRAS)
Promotes compliance with the water fittings regulations and maintains a directory of products which have been shown to comply with the Water Fittings Regulations.

Kiwa’s KUK Reg4 approval mark demonstrates full compliance with the UK Water Supply (Water Fittings) Regulations 1999, exactly like WRAS does, so can be universally accepted as equivalent to WRAS approval.

NSF (formerly the National Sanitation Foundation)
Offers a REG4 certification scheme for the UK market allowing plumbing products and materials to show compliance with the Water Supply (Water Fittings) Regulations 1999. This process is generally quicker than WRAS approval.

All three bodies use the same testing processes and standards to demonstrate compliance, therefore are considered equal.


Need to know more?

NYMAS Group products are Reg 4 compliant , which means that when you select taps, showers or other water appliances from our range, you can enjoy total peace of mind that your project is compliant. If you have questions about Reg 4 compliance, our team will be only too happy to help – email for support.