September 25, 2019

Toxic Lead Solder approved by professional plumbing organisations and used widespread in UK colleges & homes

Lead solder on Legacy Copper Home Plumbing

Is Lead Solder legal to use on Heating and Gas Systems?

Lead in the water has found that the use of toxic lead solder is widespread in UK Further Education Colleges and by Gas Safe Registered Engineers for heating and gas pipe installations. Lead Solder appears to be approved on non-drinking water supplies in recent publications by the Water Regulations Advisory Scheme (WRAS) and the Chartered Institute of Plumbing and Heating Engineering (CIPHE). Social media has brought the scale of the problem to light with hundreds of installers who are passionate about traditional techniques of using copper pipes jointed by means of leaded solder. The debate on social media has descended into arguments without deliberation of the facts against the use of lead solder vs facts presented for the continued use of lead solder. This short article reviews the evidence and presents comments from WRAS and CIPHE (see pages 30-31 here).

Water Regulations Advisory Scheme UK on Twitter

New Evidence

The harmful affects of lead are well documented in scientific publications which are often inaccessible to the general public. However, new evidence is being brought to light about the dangers of ingesting lead which causes health risks to women of childbearing capacity of miscarriage and neurological damage to the unborn child. In young children the risks from toxic lead-dust from soldered gas pipes and from lead in the water can cause ADHD and other development problems. Lead is a known carcinogen and low-level exposure can cause cardio vascular disease in adults killing millions worldwide (see here).

Article from the Lancet describes dangers of low-level explosure to Lead toxins


It appears that WRAS have drawn on out-dated regulations for their advice to plumbers and gas installers, stating that lead solder is legal for use on closed circuit heating systems and non-potable supplies which has been interpreted by some to mean gas pipes. The Health and Safety executive published that the use of lead solder is prohibited for use and has restricted sale to professional users (see here and here).

Health and Safety Executive Bulletin (2018)

It must be noted that although lead solder is legal for sale in the UK it is not allowed under World Health Organisation guidelines to be used or introduced to any system for new work or repairs (see here).

World Health Organisation Guidelines

The EU Drinking Water Directive (EUDWD) harmonised hygienic rules for materials and products in contact with drinking water on 1st Feb 2018; adopting the World Health Organisation guidelines in full (here). The EUDWD is a relevant tool to ensure the high quality of drinking water in the EU and the UK is subject to these rules. Harmful materials used in drinking water products such as lead, which is still added to the manufacturing process of brass in drinking water taps, are subject to REACH – ‘Registration, Evaluation, Authorisation, & restriction of CHemicals’. The UK is subject to EU REACH. Current EU health and safety literature strongly suggests there is no place for lead solder in any modern system and plumbers, gas fitters and professionals are duty bound to contribute to human flourishing – so must act on the side of safety in the public interest! (see here and here).

Closed Heating Systems Permanently Connected to Drinking Water in UK

There is an assumption by UK water legislative bodies that gas installers and plumbers are working to WHO guidelines. Therefore, heating systems are permanently connected to drinking water for filling via a Fluid Category 3 backflow device, because it is assumed there is no lead in the system in accordance with WHO guidelines.  

However, CIPHE and WRAS arguably promote the use of lead solder on heating systems and installers have been seen to be using it on closed heating systems (like those which have combination type boilers) which raises the Fluid Category of the system from Fluid Category 3 to Fluid Category 5 (with 5 being the highest fluid Category risk to human health). Closed Central Heating systems which are risk assessed at Fluid Category 5 are not allowed to be connected directly to the drinking water supply under any circumstances.

At present, closed heating systems are rated at Fluid Category 3 and fitted with a back flow safety device concurrent with the risk. This safety device prevents water in the heating system entering the drinking water should a backflow incident occur. Backflow of water can happen when the mains water supply pressure fails owing to a burst trunk main the road or a large fire like Grenfell Tower.

However, if the closed heating system has been installed using toxic lead solder the fluid category is raised and cannot be connected to drinking water via Category 3 device – because of high risk of backflow into drinking water. The question to WRAS and CIPHE is “if lead is to be used on closed heating systems – then are millions of boilers rated at Fluid Category 5, connected to home drinking water with the wrong type of back flow protection device?”

UK Further Education Colleges and Gas Training Centres use lead solder

Lead Solder use in UK Gas Training Centre (June 2019) has compiled extensive evidence including high definition images, screen-shots of online comments by teachers in gas training centres and witness testimonies that lead solder is still in widespread use in UK colleges in 2019. This practice stands in contradiction with WHO guidelines and HSE legislation, schedule 1 (page 89 here). Not only does this situation present an environmental health risk to people working in the college building – but the surrounding neighbourhood is put a risk of a toxic lead soup backflowing into their drinking water from the college workshops, should a backflow incident occur.

Women of childbearing capacity, young people 16-18 years old and unsuspecting adults are all at risk from toxic lead – lead dust and lead vapour from lead solder use in a poorly ventilated college workshop environment may be a significant hazard (see image above). Female cleaners are also at risk from cleaning any college premises where lead solder is used extensively on a daily basis.

We at want the public to support our aim of removing lead solder from sale in the UK and to lobby water authorities to update water regulations, along with supporting the training of plumbers and Gas Safe Register engineers. Further Education Colleges also need to upgrade their Health and Safety risk assessment to include the use of lead solder. Please leave a comment!

Author: Dr Simon Reddy