Pipework For A Lead-Free Future

Recent research has highlighted the damaging health effects of lead. With pipes and fittings transporting drinking water being one of the main sources of contamination, plumbing professionals need to remain alert to the risks and should use the latest lead-free materials for piping systems.

The damaging effects of lead on the human body are well known. Lead can be present naturally in the environment, in soil and groundwater, but was also traditionally used in petrol, paint and piping systems, including those used for drinking water. Lead is a toxic metal which can be harmful to health even at low exposure levels. But it is the build-up, or bioaccumulation, of lead in the body over time that can cause real health problems.

Research over the years has shown that this build up can cause a range of developmental and behavioural issues. Children, infants and unborn babies are at particular risk because the physical and behavioural effects of lead occur at lower exposure levels in children than in adults. In children, even low levels of exposure have been linked to lower growth rates, damage to the nervous system, learning disabilities, hearing difficulties, and anemia. Lead exposure in pregnant women is also associated with premature birth and reduced fetal growth.

However, more recent evidence, published in the British Medical Journal, has shown that the risks from lead and other environmental metals are greater than previously thought for adults as well. An extensive study by scientists at Cambridge University found that exposure to arsenic, lead, cadmium, and copper is associated with an increased risk of cardiovascular disease and coronary heart disease. This is in addition to the known detrimental effects of lead on reproductive systems and kidney function.

With the use of lead in piping systems, paint and petrol having been phased out since the 1970s, it might seem that this issue should no longer be a major concern. Thankfully, this is true to some extent in Europe where levels of lead exposure have been falling. However, as the World Health Organization emphasise, exposure to high levels of arsenic and lead is still a serious threat to public health in many low and middle-income countries.

While the threat is certainly less than it used to be, plumbing professionals should continue to be mindful of the risks and ensure that they are compliant with the latest regulations. Nowadays, exposure to environmental metals in the UK remains primarily due to persistence in past uses. Lead is no longer present within the public water supply and its incidence in groundwater is rare. Before 1970 many smaller pipes were made of lead and it is possible that lead pipes and, occasionally, lead-lined storage tanks remain in these older houses and industrial buildings.

This is more likely if kitchens and bathrooms haven’t been modernised for decades, although it is also possible that the underground service pipe connecting the water main in the street to the system in such buildings could be made from lead. If homeowners are worried about the presence of lead, a simple visual test can be carried out by locating the internal stop tap (usually found under the kitchen sink) and checking the inside pipe that’s connected to it, where the water pipe enters the property. According to advice from experts at regional water companies, if this pipe is dull grey, easily scratched to reveal a shiny silver colour and makes a dull sound when tapped, then it may be made of lead. The joint with the external pipe or stop-tap may also be rounded and swollen.

A less common problem relates to the use of lead solder. As with lead pipes, the use of lead solder in drinking systems has been banned for over 30 years. In the UK, The Water Supply (Water Fittings) Regulations 1999 prohibits the use of lead solder for joining copper pipes in plumbing systems which are used to supply water for cooking, drinking and bathing. It is still available on the market for use in closed-circuit central heating systems and, worryingly, there have been cases of unqualified plumbers and DIY enthusiasts still using it to connect pipes in drinking water systems. However, this is becoming less of a problem as traditional piping systems are increasingly being replaced by safer, better quality and more durable, press fit piping systems such as those manufactured by Sanha.

If lead piping is found, there is no need for panic. Health risks are often mitigated in hard water areas by scale building up in the pipes and protecting against the dissolution of lead into the water. If lead is detected, steps can be taken to ensure water that has been sitting in pipes is not used for drinking or bathing. In general, if the presence of lead cannot be completely excluded then it is advisable not to use water that has been standing for more than 6 hours, not to use hot water but cold water to make drinks, to take care with water softeners, which can change the composition of the water, and to avoid using tap water to make up infant formula. The pipes should, however, be replaced as soon as possible with a suitable lead-free piping system.

Fortunately, there are a number of good lead-free alternatives on the market. Using these materials for pipes and fittings guarantees that water is safer to drink, and eliminates the risk of contamination. In the UK all drinking water, whether from public supplies or other sources, has to meet standards laid down in the EU Drinking Water Directive (98/83/EC). First introduced in 1998 via the European Union, the Directive has progressively got tighter and as of 2013 the accepted content of elements such as lead in the water has been reduced to 0.01mg/l whereas the maximum was previously 0.025mg/l (a 60% reduction).

Nowadays, copper, plastics, stainless steel and bronze are all used in drinking water systems. Manufacturers such as Sanha are increasingly advocating the use of stainless steel and have also developed lead-free alloys which are specifically designed to transport drinking water.

These alloys, such as lead-free silicon bronze used in Sanha’s PURAPRESS range have a number of advantages over traditional copper, brass and gunmetal. Silicon bronze is completely dezincification resistant and is not susceptible to stress corrosion cracking - both problems that can occur with traditional brass pipework and fittings. As a premium hygienic material, it is also produced with a ‘hot stamping’ method, meaning the material is very dense and not subject to porosity like pipes made from materials like gunmetal may be. Silicon bronze also complies with all current and future regulations such as REACH / ECHA and national drinking water directives.

With new research highlighting additional health problems due to lead exposure, it makes sense for plumbing professionals to take every step possible to ensure potentially-toxic metals are not used to transport water. While lead piping is rarely used nowadays in the UK, pipework in old buildings still presents a risk, as does the use of lead solder by unqualified plumbers. When such pipework is uncovered, it is imperative that it is replaced as soon as possible with lead-free pipes and fittings made of materials such as stainless steel or silicon bronze.