Hidden Threat in UK Homes: Water Regulation Knowledge Gap

OXFORD, July 23, 2025 – Millions of UK homes could be at risk of water contamination or leaks due to a worrying ‘compliance paradox’ in Britain's plumbing regulations, according to new research by global water safety authority NSF. The study reveals that while half of homeowners have installed water fittings, such as taps, showerheads, or pipes, in the last five years, more than half (52%) are completely unaware that they bear legal responsibility if these products don’t meet regulatory standards, even when purchased from legitimate retailers.

It is a legal requirement that all water fittings connected to drinking water must comply with Regulation 4 of the Water Supply (Water Fittings) Regulations 1999, which sets the rules for water fittings in all homes connected to the public water supply.

This alarming knowledge gap creates a situation where manufacturers can legally produce non-compliant products and shops can legally sell them, yet homeowners and installers bear full legal responsibility for ensuring compliance with regulations that many don’t even know exist.

“Imagine buying a tap from a reputable DIY store, installing it yourself and then learning you’ve unknowingly broken the law and potentially put your family’s health at risk,” said Samantha Duffy, Senior Manager, Global Water Programs EU and UK at NSF. “This is the reality for millions of homeowners across Britain today.”

The comprehensive survey of 2,000 UK adults revealed that about one in five homeowners believe their property likely contains fittings that violate water regulations. This concern is even more prevalent among younger generations, with nearly half of those under 35 suspecting they have non-compliant water fittings in their homes.

• 49% of UK homeowners have installed water fittings in the last five years
• 52% had never heard of the UK Water Supply Regulations 1999
• 80% of UK adults have never checked if their water fittings comply with UK regulations
• Only 46% of property owners are aware they bear legal responsibility for compliance
• 37% incorrectly believe water fitting manufacturers are solely responsible
• 30% of UK adults assume all water fittings sold in the UK are automatically compliant with UK regulations

Non-compliant water fittings pose several serious risks. They could allow harmful substances, such as heavy metals like lead or organic molecules, to leach into your drinking water, or microorganisms, like bacteria, to thrive in your home water system. This can lead to serious health risks ranging from gastrointestinal issues to more serious long-term health concerns. Non-compliant products could also risk property damage from leaks and potential legal and financial consequences, as they could invalidate your home insurance.

“This isn’t just about following rules, it's about protecting your family’s health,” explained David Platt, Director of Water, EMEA at NSF. “Where non-compliant fittings are installed, they can introduce contaminants directly into your drinking water. The regulations exist specifically to prevent this, but they only work if people know about them.”

NSF recommends three simple steps for all UK homeowners:

1. 1. Check existing fittings: If you’ve installed water fittings recently, check that they have the proper UK compliance certification.
2. 2. Look for REG4 certification marks: When purchasing new fittings, always look for products that are certified with REG4, such as NSF REG4, which ensures compliance with UK regulations. Be cautious of very cheap products that do not mention UK compliance or certification.
3. 3. Consult a qualified plumber: When needed, work with professionals who understand water regulations.

“The good news is that compliance is straightforward once you know what to look for,” added Duffy. “Regulation 4 certification marks, such as NSF REG4, provide instant assurance that a product meets all UK water regulations, making it easy for homeowners to make safe choices.”

NSF has created a free, easy-to-understand guide to UK Water regulations available at this link.