Building pathology: lead paint

Handle with care

25 November 2009

Lead paint can exist in many of the buildings around us, says Tristan Olivier, but if not handled correctly it can have devastating effects on our health

If you want to get to grips with lead paint hazards and exposure risks, applying an asbestos mindset is a good starting point. Applying much of what you already understand about surveying and managing asbestos will give you a head start when dealing with lead and the Control of Lead at Work Regulations 2002 (CLAW).

Health and Safety Executive (HSE) guidance under Construction Occupational Health Management Essentials (COHME) advises: "Identify and collect pre-construction information - including advising the client on the need to commission surveys to fill significant gaps for example asbestos or lead surveys, if preparing pre-1960s paintwork".

During an economic downturn, there is always an increased emphasis on refurbishment and public sector work. Given young children's particular vulnerability to lead exposure risks, projects involving pre-1970 nurseries, primary schools and housing are likely to be significant sources of potential exposure risk and liability. Building surveyors, contractors, other construction professionals and their clients cannot ignore the fact, that 'lead equals liability'.

Approximately 70% of UK buildings pre-date 1970, i.e. around 18.5m homes and thousands of schools, workplaces and public buildings. Old lead-based paint is most often disturbed during work on these buildings and lead paint hazards and exposure risks can affect:

  • professionals, contractors and tradesmen
  • building owners and occupants
  • DIYers in maintenance, repairs/refurbishment and redecoration.

History

Traditionally, lead chromate and lead carbonate were widely used in oil-based paints on timber and metal surfaces. Because of its excellent elasticity and permeability, lead paint was also used on walls and ceilings in high moisture areas such as kitchens and bathrooms. In reality, lead paint can be found almost anywhere.

Being able to recognise lead-based paint in situ, though useful, is not a reliable way of confirming its presence on a particular substrate. Chemical paint stripping and/or the use of heat guns or blow torches, both of which require 'mechanical' removal with assorted knives and scrapers, tend to force quantities of lead back into the substrate. Original, visibly clean and paint-free, surfaces frequently contain hitherto undetectable lead levels that are an immediate and 'significant' exposure risk to anyone working or coming into contact with them.

Well maintained and intact lead painted surfaces, though inherently 'hazardous', do not constitute an exposure risk (as with asbestos). It is only when they deteriorate or are disturbed to become a source of lead dust, fume or vapour, that lead painted surfaces need to be treated with care.

Health and Safety Executive

At the time of writing, the Health and Safety Executive (HSE) is expected to launch its new section on lead hazards in construction, under Construction Occupational Health Management Essentials (COHME), and its new guidance leaflet on the subject.

With these improvements, the HSE is tackling this issue with renewed vigour. This is important, as anecdotal evidence suggests there is almost industry-wide ignorance and non-compliance with CLAW regulations, with increasing hospital A&E admissions for occupational lead exposures that should never occur.

The health effects of exposure to lead

You cannot see it, taste it or smell it and yet it is considered to be the most widespread environmental toxin. It can affect you and your family without any visible symptoms in ways that can damage your quality of life, for the rest of your life. Its ingestion, usually through normal hand-to-mouth activity, can result in brain damage, miscarriages and reduced fertility. In some cases, it can result in coma and death.

Recent BBC news coverage (September 2009) has also highlighted the reduced academic performance of UK children that have been exposed to lead.

There is no 'safe' level of lead in the body. Since the removal of lead additives from petrol, lead in paint is now the biggest source of exposure risk.

For the purposes of compliance with CLAW, any amount of lead dust, fume or vapour that could be inhaled or ingested is defined as a 'significant exposure' risk.

Measure for measure

Identifying and quantifying lead paint hazards and exposure risks, though, is a challenge in itself.

Chemical spot tests are an effective but not 100% reliable method for testing for the presence of lead. Even tests by an accredited laboratory will not provide 100% of the lead information you need - five layers or a single layer of paint each with 5,000ppm will always be reported as 5,000ppm/layer, even though the total amount of lead present is obviously much greater in the multiple layers.

Although a measured area of lead paint removed for laboratory analysis provides a more useful quantification of any lead present, expressed as mass of lead per unit area (i.e. mg/cm2), it is prone to inaccuracy. It is as difficult to remove 100% of the paint from a surface as it is to avoid removing some of the substrate beneath. Either way, any lead results should be treated with a degree of caution. This is always one of the limitations of so-called 'destructive' or 'physical' sampling for remote testing.

There is only one method capable of a 100% reliable, non-destructive analysis of the total lead content of unpainted/painted surfaces in situ - using handheld XRF-i (X-Ray Fluorescence-isotope) technology. This is the standard equipment used by lead-based paint inspectors and risk assessors in the US, France and Australia - but is only gradually becoming accepted as best practice in the UK.

Lead paint surveys and risk assessments

Lead surveys generally follow the asbestos Type 2 and 3 survey model, but are generally less expensive.

There is no UK action level or threshold for lead in paint as far as CLAW compliance is concerned. However, the UK definition of lead containing material to be classed as 'hazardous', for waste disposal purposes, is 0.5% lead content of the total weight of material (from Hazardous Waste [WM2] from the Environment Agency). This clearly needs to be a consideration for Site Waste Management Plans.

Interestingly, 0.5% is equal to 5,000ppm or roughly equivalent to 1mg/cm2. This is the US action level for lead paint in homes, schools and child-occupied facilities.

In the UK, the Lead Paint Safety Association (LiPSA) regularly finds lead levels between 5mg/cm2 and 40mg/cm2. The implications of this only become clear when you consider the amount of toxic lead dust that can be generated by a single square centimetre of lead-based paint.

Settled/surface lead dust (the only UK lead dust standard is for airborne dust) is measured in micrograms/ft2 (ìg/ft2) - 1mg of lead in 1cm2 of paint is equivalent to 1,000ìg (micrograms) of lead. Children's health is known to be adversely affected by lead dust levels on skin that are at or above 18ìg. So 1cm2 of this 1mg lead in paint would be enough to contaminate 55ft2 of floor. Now do the numbers for the lead contamination from 40mg/cm2. And remember, 40mg/cm2 could easily signify the accumulation of dozens of layers of paint all of which have a concentration of only 5,000ppm.


Dust wipe sampling of lead dust levels is a highly effective method for ongoing monitoring of personal hygiene and RPE/PPE cleaning routines

At the end of a project, dust wipe sampling can also be carried out as a clearance test before premises are reoccupied.

Until recently, a blood analysis of lead levels was the only 100% reliable way of establishing current levels of individual occupational exposure. This is a legal requirement for those subject to 'significant' exposure arising from the risk of inhaling or ingesting lead dust, fume or vapour. Traditionally, this has required the inconvenience, cost and pain of having a blood sample taken. However, pain-free and easy-to-use saliva test kits are now available that will quantify lead levels in blood as accurately as a blood analysis.

Managing lead paint hazards and exposure risks

Original building components such as windows, skirtings, doors, door frames and staircases, can be a source of lead dust exposure even if older lead-based paint coatings have already been stripped off. Old metal railings and structural metalwork also tend to have been coated with lead-based paint.

Important aspects of lead-safe working include:

  • removing/protecting furniture and movable items
  • working wet
  • avoiding heat guns and naked flames (which generate highly toxic lead fumes at temperatures above 450°C)
  • very careful personal hygiene
  • using suitable respiratory and personal protective equipment
  • regular cleaning up and 'HEPA' vacuum cleaning (with machines rated for 'hazardous dust').

Case studies

LiPSA seems to spend more time helping out contractors who have been 'forced' to address lead exposure issues after a project has started, than providing that all-important input during the pre-construction phase.

Requests for lead surveys and risk assessment advice usually come from contractors who have managed to 'miss' potential lead issues. These are generally identified by operatives or other building occupants, which means there is pressure on the contractor and client to be seen to be proactive in addressing a potentially significant compliance oversight.

Once potential lead exposure risks are suspected, work is usually stopped - just in case. After the full extent of lead hazards and likely exposure risks are identified and appropriate actions advised, few seem to recognise the value of further expert input. However, in the wake of Channel 4 TV's special report on occupational lead exposure oversights (5 November 2009), this has now started to change. Anecdotal evidence would seem to suggest that once the consequent programme delays and additional costs of dealing with lead hazards are taken into consideration, most contractors and clients choose to gloss over the problem.

Regrettably, because of potentially significant legacy and ongoing liabilities, it is not possible to cite examples of good or bad practice. Whether projects involve hospital, prison or social housing refurbishment - the discovery of lead 'issues' half-way through multi-year programmes has meant that there will always be contradictory forces at play to balance commercial self-interest with legal obligations and the need to 'do the right thing' - even if lead-safe work practices are implemented for the rest of a project.

What can you do when a paint manufacturer's specification for a given job warns about the need for "special precautions on pre-1960s paintwork on wood and metal surfaces which may contain harmful lead" and the sub-contractor claims complete ignorance of the problem? Main contractors, generally, don't want to know; CDM Co-ordinators don't want to have been caught out and clients would rather deny all knowledge and avoid the extra costs. CLAW compliance will be considered by some to be yet another unwelcome but necessary addition to more widely acknowledged health and safety concerns.

Conclusion

The UK's lead legacy will certainly outlive most of us, providing an ongoing source of liability, and opportunity, for surveying professionals. Until the weight of lead in paint samples is expressed in terms of the sample size from which they come, whether using laboratories or handheld XRF-i equipment, we are kidding ourselves about the true extent of the lead exposure risks that are being created. And without a 'real' measure of lead hazards, it is impossible to quantify and manage potential exposure risks.

There have been important advances in lead paint, dust and blood analysis capabilities, most of which are as accessible to the general public as they are to professionals. CLAW compliance isn't necessarily difficult or particularly expensive, but the price of ignoring a better informed and equipped public could be incalculable.

Tristan Olivier is a Lead Paint Inspector and Risk Assessor with the Lead Paint Safety Association

Further information