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Lead Use in the UK
Here are some examples of lead use in the UK that may differ when compared to other developed countries.
Flashing
Many, or even most, buildings in the UK, especially domestic, have some external lead flashing, i.e. sheet lead used to prevent water ingression around chimneys, windows, doors and roof valleys. This includes properties of all ages, even new builds.
Older
For example, this house appears to have lead flashing around the chimneys, dormer windows and over the front door.
Photo: © Copyright Graham Horn and licensed for reuse under this Creative Commons Licence.
Newer
The house below looks like a mid-20th century build or conversion. Lead appears to have been used on top of the dormer windows and beneath each light. There also appears to be a strip beneath the bottom row of tiles.
Photo: © Copyright Oast House Archive and licensed for reuse under this Creative Commons Licence.
New
This picture, from a home builder’s web site, appears to show lead being used between the walls and ground floor roofs. It could be some other material of course.
Regulations
One roofing information source called ‘Roofconsult’ makes the following comment: ‘The UK is the main user of lead sheet in Europe, as most countries consider it a poison. Lead is poisonous when ingested, so all health and safety recommendations need to be complied with when working with the material.’
That would be fine, but our Control of Lead at Work (CLAW) regulations state that ‘Handling of clean solid metallic lead, e.g. ingots, pipes, sheets etc.’ is ‘Work not liable to result in significant exposure’. Maybe that is true, but I would like to see some evidence to support that contention in the regulation. Our ‘Control of Substances Hazardous to Health (COSHH) Regulations 2002’ do not help as they specifically exclude lead and refer to CLAW.
Risks
What needs to be considered is whether lead sheet when used as a building material presents any risk to health. The best way to know is to do a Blood Lead survey of roofers and other building workers.
Run Off
The Lead Sheet Association make the following statement “lead sheet forms a natural patina or surface protective film that is both strong and adherent.” This does not seem to be consistent with the findings of Magyar et al, 2014, who state “Lead concentration in tank water exceeded Australian Drinking Water Guidelines for all roof types where there was lead flashing.” The Lead Sheet Association say that “Any minute products of corrosion washed off during the lifetime of a roof become highly diluted in rainwater”, but this does of course depend on the volume of water. It would appear that in the case of the findings in the Australian study the dilution was not sufficient.
The Netherlands National Water Board in 2008 report stated that “Corrosion and subsequent runoff of lead is a major source of lead in surface waters”, but do not state whether the quantity is considered hazardous to health.
Accessible Solid Lead
Perhaps because use is less in countries other than the UK, it is hard to find any research to help understand the impact on health risks from metallic lead used in building.
A blogger called ‘The Roofer’ in one piece called ‘Lead Flashing: Is It Dangerous’ states that lead sheet “forms a tightly adherent, stable patina of virtually insoluble lead compounds”. My own tests, see below, show that, in one case, the lead is not so tightly adherent as that. In fact, it was easily rubbed off.
‘The Roofer’ references The European Lead Sheet Industry Association brochure. In this brochure, ELSIA acknowledge that those working with lead should wear gloves, wash hands before eating and drinking, and wear a dust mask while handling old lead sheet. Fair enough, but a child, or anyone ignorant of this advice, would not be likely to follow these practices. Not all sheet lead is beyond reach – EILSA would do well to advise that this should always be the case. It would also be good if warnings were included in standard home buyer’s surveys where accessible lead is present which could include windows with lead flashing below them or with decorative lead cames as shown below.
Underside corrosion
A report by Cathedral Communications on their Building Conservation web site on “Underside Condensation and Corrosion of Lead Sheet Roofs” notes that conditions on the underside of lead sheet may not promote the development of a protective patina. This can therefore reduce the expected life of lead.
Bioavailability
In order to assess the risk from lead flashing it might be useful to consider whether the lead compounds formed by weathering are ‘bioavailable’. For this article this is considered to be whether a substance enters the circulation, i.e. influences blood lead levels.
The process of lead patination is understood to include the following steps as described by Guardian Industries Goole Ltd, UK, in The Oxidation of Lead.
Lead -> Lead oxide -> Lead carbonate -> Lead sulphite -> Lead sulphate
The final patina has approximately 30% lead sulphite, 60% lead sulphate and 10% lead carbonate, but this varies depending on conditions.
It is understood that lead oxide and lead carbonate are more soluble than lead sulphite and sulphate which might suggest that the risk reduces with time, but further analysis would be needed to quantify this.
Risk Management
Patination
When lead flashing is exposed to moisture it forms lead carbonate which does not adhere to the flashing and the resultant white powder can be washed by rain onto other surfaces. To prevent this, patination oil can be applied as described by British Lead. Whether this is just an aesthetic advantage or prevents release of lead compounds is not explained.
LeadCheck Test of 90 year old Lead Sheet
Any claim that lead sheet forms a protective insoluble coating can easily be investigated. In a simple test I rubbed a cotton bud on 90 year old lead sheet.
I then dipped another cotton bud in mixed reagent from a LeadCheck swab. The two cotton buds were rubbed together as shown below. The result was that both cotton buds turned strong pink showing that lead was present.
Conclusion
I cannot argue that lead is not a useful building material. What is hard to assess is whether the benefits outweigh the risks of personal and environmental contamination. What seems to be established is that roofs bearing lead flashing should not be used as a source for drinking water and the lead flashing should not be touched without personal protection equipment, e.g. gloves.
More warnings in home buyer’s surveys, and for potential renters of buildings, and on replacement windows where lead is accessible, would seem to be low cost ways to start to manage the risks of external building lead.
Lead Cames in Leadlighting
Lead cames (the lead that hold the panes of glass ‘quarries’ together) are a fairly common sight not only in older buildings, but also as decoration on the outside of double-glazing in new builds or replacement windows or furniture such as kitchen cabinets
Examples
The house below looks like a typical early 20th century build, or perhaps older, with leadlighting in diamond pattern.
Photo: Free for commercial use. No attribution required.
You might recognize this next house from a Harry Potter film. I am not sure that ‘defence against the dark arts’ would help with all that lead.
Photo: Dave Catchpole Some rights reserved.
Risk
It has been noted that lead from cames can be a source of contamination (al-Radady, Davies and French, 1993) – “Corrosion of ‘cames’, i.e., the lead binding or decorative strips in leadlight windows, is a significant, but previously unreported source of lead within older homes.”
Lead on Window Quarries
In a DIY-sampling lab test I found that condensation on the glass of leaded windows (leadlighting) contains detectable lead. This was shown by applying a LeadCheck swab which readily turned pink. An extended test showed that the lead contamination can be removed by cleaning with a baby wipe, but then returns after a couple of weeks. It should be noted that these cames had been treated with patination oil which it was hoped would reduce the release of lead, but not so in this example.
Lead from Cames onto Sills
Laboratory dust wipe tests of the internal sills below some leaded windows showed the following levels of lead before cleaning.
Inside 64.2 µg Pb/ft2 (micrograms of Lead per foot squared)
Inside 70.4 µg Pb/ft2
Inside 63.8 µg Pb/ft2
Inside 61 µg Pb/ft2
Outside 63 µg Pb/ft2
Sampling followed the United States Environmental Protection Agency Lead Dust Sampling Technician Field Guide followed by analysis by inductively coupled plasma mass spectrometry.
These values are within the USA Housing and Urban Development lead hazard and clearance action levels as of 1st April 2017. For window sills the level is < 100 µg Pb/ft2.
Cleaning Cames and Quarries
I conducted some testing on different cleaning methods to see how much lead was deposited from the cames and quarries to the horizontal surface below. Sampling and analysis was as above. In each case a smooth clean board was placed beneath the window being cleaned. The cleaned sample board was tested before and in-between tests and the Lead result was <4 µg Pb/ft2.
Method µg Pb/ft2
1) After brushing the cames with bristle brushes and oven blacking 5690
2) After cleaning with baby wipe and polishing with kitchen paper towel 208
3) After cleaning with a purpose-made window wipe 59
4) After cleaning with a window vacuum cleaner similar to this (photo) 106
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The windows had recently been installed and the lead cames were subject to condensation.
Test notes
Cleaning method to clean the board in between each test - Using baby wipes removed lead contamination to sub-detectable levels even after the highest level of contamination in these tests.
Cleaning method 1 was that performed by the installers of renovated windows. They have been told of the results, but have not acknowledged a change in practices. |
Cleaning method 2 - Polishing with a paper towel results in more contamination.
Cleaning method 3 - Using purely a window wipe produced the least contamination, but did leave smears on the glass.
Cleaning method 4 – After use the blade of the window vacuum cleaner was tested with a LeadCheck swab and showed positive for lead meaning that lead could possibly be transferred to other windows as, unlike the other methods tested, the blade is not disposable.
The lesson learned here is that the window board beneath the windows should be cleaned with a baby wipe after cleaning the glass and cames. Cleaning with disposable baby wipes is not environmentally sustainable so the next logical test would be to clean with reusable washable wipes and a lead specific detergent such as sugar soap.
It should be noted that these are single DIY-sampling lab tests and the results may not be repeated in other cases.
Cleaning
A window supplier, Guardian Industries, Goole Ltd of York, suggest that "After glazing, the lead should not be cleaned with solvent based or abrasive cleaners, as this may cause the oxidation process to begin again on any re-exposed 'fresh' surface"
The Australian Government, Department of the Environment and Energy seem to have the most authoritative advice on ‘Lead in Stained Glass’ which should apply to any leaded glass (Leadlighting).
“Lead cames oxidise, causing a white powdery coating that rubs off very easily.
“Any cloths and other cleaning equipment used should not be used for cleaning anywhere else, otherwise you could easily contaminate other parts of the house.”
In my experience this advice is not always provided in the UK. We should perhaps see if the relevant industry associations can be persuaded to provide it as standard.
Patination Oil Failure
This is an example of the use of lead cames. Some new windows had been installed with decorative lead cames. These were supposed to have been treated with patination oil by the manufacturers. However, soon after installation they were exposed to rain and this resulted in what appears to be lead salts running off the cames and onto the glass and sill below. This was confirmed with a LeadCheck test.
It would seem that application of patination oil does not work in these conditions, or the manufacturers failed to apply the oil properly, if at all.
Conclusion
From these pieces of advice, and DIY-sampling lab tests, it would seem that some lead can be released from lead cames and this can be significantly increased by the wrong kind of cleaning. However, the released lead can be cleaned up easily and effectively. This concurs with the US EPA advice “Wipe down flat surfaces, like window sills, at least weekly with a damp paper towel and throw away the paper towel.” Again, a wet cloth with a lead-specific detergent is more environmentally sustainable than discarding paper towel.
What is not known is whether lead dust resulting from external corrosion can be drawn into the air and inside the home when windows are opened.
uPVC
Over the past few decades many homes in the UK have been built or renovated with uPVC windows. This picture shows a typical example of before and after:
Photo: The copyright on this image is owned by Stephen Richards and is licensed for reuse under the Creative Commons Attribution-ShareAlike 2.0 license.
This should have been very good for lead poisoning prevention because it meant that old wooden, lead-painted, window frames have been removed. However, it seems that lead compounds were used as plasticisers in uPVC.
Risks
Lead Content
The British Plastics Federation state that the amount of lead in uPVC is 0.5 to 2.5% and add that this “does not represent any significant risk of damage to health.” However, the justification for this is based on pipes. They quote a report (which I cannot find) which apparently states “it is just as safe to eat meals off a lead stabilised PVC pipe as it is to eat them off a ceramic plate”. I am happy to hear that, but that is pipes. Windows are subject to one significant difference – sunlight.
Lead Release
A group called “Say No To Vinyl” have collated many quotes referring to the degradation of uPVC windows in sunlight and Yousif and Hasan, 2014, stated “UV radiation causes photooxidative degradation which results in breaking of the polymer chains…. leading to useless materials, after an unpredictable time.”
LeadCheck Test of uPVC windows exposed to sunlight
A simple test on examples of uPVC windows exposed to sunlight, both internal and external, with a LeadCheck swab, revealed the presence of lead. This could be because the tartaric acid in the LeadCheck reagent etches into the plastic and releases lead, but then perhaps some other acids could do the same.
Restrictions
A voluntary initiative has resulted in members of the European Stabilisers Production Association (ESPA) replacing lead stabilisers by the end of 2015. This is great, but of course leaves many windows in place which will degrade over time and potentially release lead. Also, it does not seem to be clear whether this voluntary agreement applies to manufacturers who are not members of the ESPA. Perhaps manufacture outside Europe is not constrained.
Conclusion
There seems to be nothing to stop uPVC windows degrading and releasing lead. Further research would be needed to determine whether this might cause a risk to health. At least it might be advisable that cloths, and other materials, used in cleaning uPVC should not then be used for other purposes, unless thoroughly rinsed first.
Paint
Like many countries lead was used historically in paint in the UK. Unlike many other countries we have never ratified the Geneva White Lead Convention of 1921.
Dates
Some of the key dates that apply to the UK have been source from ‘Lead & Public Health: Dangers for Children’, Erik Millstone, 1997.
1927 – Control of lead in paint in factories
1963 – Voluntary agreement to label paint with more than 1% lead when dry and accessible to children, but only by members of the Paint Makers Association and not to imported product
1974 – The voluntary agreement changed to 0.5%
1987 – Cessation of the use of lead in decorative paints and varnishes
1992 – European Union legislation implemented in the UK which bans addition of white lead in paint except for historic buildings
2015 – The ban on lead chromate in road paints is delayed on request of Domion Color Corporation of Canada. However, the Swedish government have taken the EU to court over the decision.
Rules
Unlike some countries, e.g. France where homes built before 1949 require testing, the UK has no rules about testing for lead paint on sale or rent; or for inclusion of lead in home buyer surveys. I believe we have no rules for disclosure; no formal lead safe contractor training or certification; no renovation, repair and painting rules; and little public information.
Warnings about Lead in Paint
Packaging on paint and abrasives sometimes includes warnings about taking precautions, but rarely describe what those precautions should be or where to find more information.
Information about Lead Paint Management
The Department for Environment and Rural Affairs has a web page which is useful, but limited and the link to ‘further information’ leads nowhere. I have told them about this months ago.
The British Coatings Federation (BCF) have a useful guide on lead paint which is broadly in line with the USA Lead-Based Paint Renovation, Repair, and Painting (RRP) Program rules. The BCF “Updated lead paint guidelines” also includes lists of service provides in the UK for lead testing and further information.
Resources for Home Tests for Lead
It is hard to find products in the UK to help determine whether paint contains lead. One major retailer, B&Q, recommends testing for lead on pre-1960s doors with test kits, but does not actually sell them. I have suggested to them that they should. Specialist retailers do have stocks of LeadCheck, and they can be found on Amazon, but not, in my experience, in the average DIY store. However, I have not found a retailer of D-Lead Test Kits in the UK.
What I would really like to see is B&Q, and other DIY stores, hand out paint stirrers like this from the USA, which says: Sherwin Williams WARNING! If you scrape, sand or remove old paint, you may release lead dust. LEAD IS TOXIC. Contact the National Lead Information Hotline at 1-800-424-LEAD or log on to www.epa.gov/lead
Lead-contaminated Feed for Livestock
The Food Standards Agency, Northern Ireland reports that “More than half of on-farm food safety incidents reported to the Food Standards Agency are caused by lead poisoning each year.” This makes it the biggest problem of its kind in the UK and includes cattle, sheep, pigs and poultry. In 2008, 2,500 animals were restricted from the food chain. How many were not detected is, of course, not known.
Leaded Antiques
Antique items are popular in the UK. There seem to be no warnings provided on sale of antiques, e.g. furniture, ceramics, about how they should be used safely. This might be an unreasonable requirement for small retailers and charity shops.
Acid Dipping to Remove Lead Paint
Reclamation of old doors and other removable building components or furniture is popular in the UK. These are often ‘dipped’ in a bath of paint stripper and then washed in water. This service is often provided by small businesses. The issue is that not all the lead is removed. Furthermore, because the bath of paint stripper is used for many doors, lead can be transferred from one door to another.
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