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Paint Film Components – Outline of
New Book
By Mike van Alphen, Lead
Sense, PO Box 3421, Rundle Mall South Australia 5000
Paints have to be weatherproof, physically
stable long-lived materials that are resistant to biological, physical and chemical
attack. In the past that has often resulted in many familiar, toxic, long-lived chemical
products being included in paint formulations. It is also those compounds that are highly
colourful that were popular in older paints.
To find that arsenic, asbestos, cadmium, lead, mercury, PCB, and
radium among many other compounds and materials have been included in paints should be no
great surprise.
Paint Film Components, was published in June 1998 and written to
explore the history of paint formulation and those many potentially toxic paint
components.
Lead in paint is best known for having caused poisonings but there
are instances where arsenic and mercury have caused harm. Many of the other potentially
toxic materials in paints are much less well understood in terms of their human health
related impacts. This book deals with the ‘long-lived’ components of paint
films. While the volatile components of paints are increasing the subject of attention and
the impacts of tin, and copper toxicity on marine life are well documented these matters
are not dealt with in any detail.
So how many kilograms of lead is
in the paint of your house?
Australian houses built in the
1920’s could readily contain 200 to 600 kilograms of lead in that thin coating of
paint.
Cans of white lead paint and white lead pigments were sold by the
pound - not by the gallon prior to the 1950’s. The hallmark of a quality paint would
have been a paint can so heavy that you wouldn’t want to carry it too far.
Assuming that you have several hundred kilograms of lead on the side
of a house how much would have to fall off to raise the soil lead concentration to a
significant level. The book shows a number of examples.
Asbestos turns up in many old paint formulations under the guise of
a range of synonyms. Short fibre length asbestos was a low-cost waste product from the
asbestos fibre industry. A hardy material, cheap and having good properties in providing
‘tooth’ to undercoat layers so that subsequent paint layers would adhere firmly.
The toxicity of asbestos fibres and their characteristics when incorporated in paint and
subsequently liberated from paint is simply unknown. Asbestos fibres are readily observed
in Australian paints but again the liberation and exposure is not well understood. Bridge
paint undercoats for example could readily contain 10% asbestos by weight in the dry film.
Painters would be the first group to investigate in relation to asbestos. This would be an
important study to conduct.
Insect, fungus, mould and bacterial attack of paints has resulted in
some of the more curious and toxic additives in paint. Pentachlorophenol, DDT and mercury
are some of the materials that turn up as additives for these purposes. Some rare paint
formulations are to be expected in industrial buildings and on industrial and scientific
equipment.
Paint Film Components is available
for $15 from:
Public and Environmental Health Service
Department of Human Services
PO BOX 6
Rundle Mall SA 5000
phone (08) 8226 7107
Reference
van Alphen, Mike (1998) Paint Film Components National Environmental
Health Forum Monographs General Series No 2. National Environmental Health Forum
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