October 2, 2019

Millions of combination boilers connected illegally to central heating systems containing toxic lead

This is the second paper in a series to support our campaign for World Health Organisation “International Lead Poisoning Prevention Week 2019”

The literature

The May/June (2019: 30) issue of the Chartered Institute of Plumbing and Heating Engineering (CIPHE) Journal ‘P&H Engineering’ stated:

Chartered Institute of Plumbing and Heating Engineering (p.30-31 here)

In the reference that CIPHE make to ‘New Regulation’, they imply that Lead is legal on closed-circuit heating and gas systems, in regard to The Water Supply (Water Fittings) Regulations. However, the reference to Regulations lacks ‘Accuracy and Rigor’ because it is ‘undated’ in their journal publication and hence misleading. We asked for clarification from CIPHE but they did not reply. CIPHE have a responsibility and duty of care to abide by the Engineering Council ‘Statement of Ethical Principals’ (here) and the publications must be robust.

Edit (20/10/2019) – since publishing this paper reported CIPHE to the Engineering Council for breaching their ethical code of conduct – The Engineering Council replied saying CIPHE can say whatever they like because the Ethical Standards published by Engineering Council are only guidelines! can only assume CIPHE are making reference to ‘The Water Supply (Water Fittings) Regulations 1999’ which is the closest match to their cited reference to The Water Supply (Water Fittings) Regulations. For the purpose of this paper, only make reference to the legality of lead solder use on heating systems in England and Wales because Scotland and Northern Ireland are subject to different Water Regulations and not mentioned at all by CIPHE. The legality of lead solder on gas has already been addressed by leadinthewater (here) and will not be included in this argument.

See 1999 Regulations (here)

The Association of Plumbing and Heating Contractors (APHC) also made the following statement in regard to the implication that Lead solder use is legal:

Association of Plumbing and Heating Contractors Press Statement (here)

APHC state confidently that it is “fact that lead solder can legally be used on non-drinking water installations where the water is not required to be wholesome, such as closed circuit central heating systems”.

leadinthewater sought clarification and contacted who are funded by the water industry to help customers find competent and qualified plumbers – CIPHE and APHC amongst other organisations, are Partners with Watersafe UK. Watersafe also state “Solder containing lead can only be used on water installations not used for drinking, such as closed central heating systems” (see below):

The Water Regulations Advisory Scheme (WRAS) produce a water regulations guide to help plumbers interpret regulations. WRAS are “Making sure your plumbing system is installed and used in accordance with the requirements of the water Supply (Water Fittings) Regulations and Byelaws in Scotland”. WRAS state that these instruments are not only legal requirements but vital in making sure the water water supply remains safe. The WRAS interpretation of the water regulations regarding lead solder use on heating systems are explicit and were published on Twitter:

It must be noted that WRAS are what it says in their title – an advisory scheme – they are not a water regulator and do not regulate on water supplies in any way (see here). Ofwat (The Water Services Regulation Authority) is the economic regulator of the water sewerage sectors in England and Wales responsible for ensuring the companies provide good-quality, efficient services at a fair price. The Drinking Water Inspectorate (DWI) are responsible for regulating water quality – are still awaiting a response from DWI.

The Argument

In accordance with the Revision of the EU Drinking Water Directive (here) and World Health Organisations guidelines (here) leadinthewater argue that lead solder is illegal and not allowed on any systems in UK buildings. However, for the purpose and clarity of this argument, will only make reference to ‘The Water Supply (Water Fittings) 1999’ (here). Our argument has two strands:

The first strand of argument – leadinthewater have been unable to find the legislative source of statements about legality of lead solder use on heating systems in England and Wales in 2019. In a word search of ‘The Water Supply (Water Fittings) Regulations 1999″ for the terms lead, solder and lead-solder there are no returns suggesting that these words are not contained in the legal document at all. This means that The Water Supply (Water Fittings) do not say lead solder is allowed but neither does the instrument state that lead solder is prohibited!

It is our argument that use of lead solder on heating systems is not a Regulation but only a guidance note or ‘recommendation clause’ in the Water Regulations/Bylaws (Scotland) guide published by WRAS.

The WRAS guidance and ‘recommendation clause R2.12‘ in the WRAS guide cannot be reproduced without consent, as they are protected by copyright. In our words the recommendation clause states that soft solder containing lead may be used for heating systems and where water is not required be be wholesome. Thus, the statements from CIPHE, Watersafe, APHC in regard to the use of Lead Solder on heating systems are not coming from the current Water Regulations but from a WRAS ‘recommendation’ (R2.12 in the WRAS Water Regulations Guide).

This is particularly worrying in that WRAS R2.12 ‘recommendation’ means a proposal as to the best course of action – especially one put forward by an authoritative body, for the use of lead solder on heating systems in 2019.

The second strand of argument – the following sections of ‘The Water Supply (Water Fittings) Regulations 1999’ will be referred to for our argument that the use of lead solder is illegal on closed heating systems in England and Wales:

Section 3. (2) (i) suggests that no water fitting shall install be installed, connected, arranged or used in such a manner that it causes or is likely to cause contamination of water supplied by a water undertaker.

It is our argument that closed heating systems in England and Wales are permanently connected to water supplies by means of a filling loop which consists of an isolation valve, flexible hose and double check valve (used to prevent backflow from the heating system into the drinking water supply should a fault situation occur – such as a drop in pressure on the filling side).

Typical filling loop for closed system central heating (Toolstation here)

This type of filling loop is suitable for a fluid category 3 risk which is outlined below – there are different risks imposed on water systems supplying different domestic and commercial applications and the degree of risk has to be matched to the appropriate provision for protection of the water supply should a fault situation arise. A fluid category 3 device is appropriate for systems where the risks present only a slight health hazard – should any water flowback into the drinking supply during a fault or backflow incident. A fluid category 3 risk means the concentration of substances say in a heating systems system are of low toxicity.

Fluid Categories which help to assess the risk of contamination on water systems

However, argue that the use of lead solder, a highly toxic substance, on a heating system raises the fluid category from level 3 to level 5. Fluid category 5 substances are very toxic and represent a serious health hazard.

The World Health Organisation (WHO) has classified lead as one of ten chemicals of major public health concern which are “highly hazardous and can negatively affect our health and environment when improperly managed” (see here). The UK Health and Safety Executive state that Women of child bearing capacity are prohibited from using lead solder and females are not allowed to clean premises where lead solder is used extensively – young people under the age of 18 are also prohibited from using lead solder (see here).

If the heating systems fluid or contents is risk assessed at fluid category 5, then the current means of backflow protection being a filling loop with double check valve, rated a fluid category 3, is inappropriate and not in accordance with ‘The Water Supply (Water Fittings) Regulations 1999’. Thus, the use of lead solder on a heating system also breaches 2. – (1) and (2) (a) and (b) of the 1999 Water Regulations because the backflow arrangement or device is not suitable or appropriate for maintaining the safety of the drinking water supply:


leadinthewater have argued with reference to the ‘The Water Supply (Water Fittings) Regulations 1999’ that lead solder is illegal for use on heating systems and current backflow provision on heating systems of double check valve is inappropriate when said system is assessed for risk at fluid category 3. have assessed heating system contents at Fluid category 5 when lead solder is used in the construction of materials and fittings in the installation and appropriate protection of the drinking water should apply. There is no legitimate regulatory support for the use of lead solder on closed central heating systems in England and Wales and it is our understanding that millions of boilers are connected illegally to home drinking water supplies, risking the health of persons.

We look forward to replies!

Author Dr Simon Reddy