From ancient Rome to modern times lead has been used as a pigment in paint coatings.
- Lead tetroxide, red lead, is a bright red or orange pigment most often used as a pigment for undercoat paints for iron objects.
- Lead (II) chromate is a yellow pigment also known as chrome yellow, chromic acid lead(II) salt, canary chrome yellow 40-2250, chrome green, chrome green UC61, chrome green UC74 and various other names.
- Lead (II) carbonate, white lead, is a cream-coloured pigment.
In addition to its visual properties, lead is added to paint to speed drying, increase durability, retain a fresh appearance and resist moisture which can cause corrosion and failure of unprotected materials. Clearly there are many desirable features of lead-containing paints, however, its interaction with the human body has given rise to its use being banned in the UK since 1978.
What Are the Dangers and Health Risks of Lead Paint?
Although lead improves paint performance, it is a harmful substance. It is especially damaging to children under the age of six whose bodies are still developing. Lead causes nervous system damage, hearing loss, stunted growth, reduced IQ and delayed development. It can cause kidney damage and affects every organ system of the body. It also is harmful to adults and can cause reproductive problems in adult men.
Due to containing both lead and chromium, paint containing lead(II) chromate is extremely toxic. It is a known carcinogen, developmental toxicant and reproductive toxicant.
One myth associated with lead-based paint is that the most common cause of poisoning is eating leaded paint chips. In fact, the most common pathway of childhood lead exposure is through ingestion of lead dust through normal hand-to-mouth contact during which children swallow lead dust that has become dislodged from deteriorated paint or lead paint dust generated during remodelling or painting works.
Where Can You Find Lead Paint?
Houses built before 1978 often have lead-based paint in them. Lead-based paint can appear on walls, ceilings, porches, blinds, fixtures floors, cabinets and virtually anything painted before 1978 when lead-based paint became outlawed
Old lead-painted surfaces which are of particular concern are those which:
• are allowed to deteriorate and which are flaking, cracking or chipping
• rub and chip or form dust
Inappropriate preparation and removal of surfaces containing old lead paint during renovation and repainting work can create an additional source of lead-containing dusts and fumes which can be both ingested and inhaled.
Before the early 1960s, white lead (lead carbonate/lead sulphate) was the principal white pigment in primers and topcoats applied to wooden surfaces inside and outside homes and other buildings. Doors, architraves, window frames and sills, stairs and bannisters, skirting boards, weatherboards, door frames and barge boards are examples of where lead-based paints might be found.
Red lead and calcium plumbate primers might be found on garden gates and railings, guttering and downpipes and other external iron and steelwork, whilst white lead, the principal white pigment in primers and topcoats applied to wooden surfaces, can be found in many places such as doors, architraves, window frames, stairs and bannisters.
Professional decorators and builders should also be aware of the possible presence of lead paints in commercial properties, industrial sites and institutional buildings such as schools, hospitals etc and take appropriate precautions when removing or renovating surfaces.
What Can Sandberg Do to Help?
Sandberg can offer a comprehensive service to both the historical conservator or individual homeowner to establish the level of lead in their paintwork. Our well equipped, UKAS accredited laboratory can undertake analysis to determine levels of lead in submitted paint samples or our experienced staff can visit site to carry out a survey of the paint systems present and take the appropriate samples for analysis. Providing you with important information will give you peace of mind and allow you to undertake any appropriate measures with your existing paintwork.
There is no specific limit for lead in paint but, for guidance, the HSE Control of Lead at Work Regulations, 2002, Section 65, classes lead contents of less than 1% Pb as being in a category where work with lead is not liable to result in significant exposure.
For lead levels exceeding this value, an appropriate risk assessment, as detailed in Section 54 of the above publication, should be carried out.