Lead paint
Toxicity
Main article: Lead poisoning
Although lead improves paint performance, it is a dangerous substance. It is especially damaging to children under age six whose bodies are still developing. Lead causes nervous system damage, stunted growth, and delayed development. It can cause kidney damage and affects every organ system of the body. It also is dangerous to adults, and can cause reproductive problems for both men and women.
One myth related to lead-based paint is that the most common cause of poisoning was 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 dislodged from deteriorated paint or leaded dust generated during remodeling or painting. Lead dust from remodeling or deteriorated paint lands on the floor near where children play and can ingest it.[citation needed]
Regulation
The European Union has passed a directive controlling lead paint use. The United States government banned lead paint by the Consumer Product Safety Commission (16 Code of Federal Regulations CFR 1303).
Lead paint in art
In art, lead white is known as flake white, also sometimes known as Cremnitz white. Flake white is traditionally considered to be the most structurally sound underpainting layer for oil painting, possessing a combination of flexibility, toughness, and permanence not found in other paints, and certainly not in the other white pigments. Genuine flake white is difficult for artists to obtain in many countries, even though other toxic paints (such as the cadmium-based colors) may be readily available. Where flake white is currently available to artists, it is usually only in small tubes designed for painting, not in the larger cans traditionally used for underpainting (coating the canvas prior to the actual painting) which for centuries was flake white’s most important purpose.
Artists’ use of lead paint is mostly associated with oil painting on linen or cotton canvas. In the relatively rare cases where it has been used in works on paper, it will often become discolored over long periods of time. This is due to the reaction of the lead carbonate in the paint with traces of hydrogen sulfide in the air and with acids, often from fingerprints. As a result, many older works on paper that used lead paint now show some discoloration.
Substitutes
Paint manufacturers replaced white lead with a less toxic substitute, titanium white (based on the pigment titanium dioxide) which was first used in paints in the 19th century. (In fact, titanium dioxide is considered safe enough to use as a food coloring and in toothpaste, and is a common ingredient in sunscreen.) The titanium white used in most paints today is often coated with silicon or aluminum oxides for better durability. Titanium white has been criticized for leading to “chalkiness” when mixed with colors, and the possibility of decreased permanence of organic pigments mixed with it due to its high refractive index.
Zinc white is less opaque than titanium white, and is often seen as a superior white for lightening other pigments in mixtures. Although zinc white is the standard white for the watercolor medium it has long been of debatable permanence in oils. Critics of the pigment argue that its use leads to excessive cracking and delamination, even when very sparingly mixed with other pigments such as lead white.
Some art-supply manufacturers supply a “lead white hue,” a mixture, usually of titanium and zinc white, which attempts to imitate the hue of genuine lead paint without the toxicity. It does not, however, have the desirable structural (physical) properties of lead white.
Real estate maintenance and renovation
Humans can be poisoned during unsafe renovations or repainting jobs on housing that has lead paint. Therefore, it is encouraged to carefully stabilize any deteriorated (peeling, chipping, cracking, etc.) paint in a lead-safe manner and take precautions during preparation for repainting.
See also
Lead-based paint in the United States
Lead-based paint in the United Kingdom
Environmental issues with paint
References
^ http://www.reuters.com/article/healthNews/idUSTRE57O64G20090825
^
^ For further discussion of this issue, see Ralph Mayer’s classic work, The Artist’s Handbook of Materials and Methods.
^ Claire L. Hoevel (1985). “A Study of the Discoloration Products Found in White Lead Paint”. The American Institute for Conservation: Book and Paper Group Annual 4. http://aic.stanford.edu/sg/bpg/annual/v04/bp04-04.html.
^ “Zinc White Problems in Oil Paint”. http://naturalpigments.com/education/article.asp?ArticleID=127. The Smithsonian’s Museum Conservation Institute exposes long-term problems with zinc white
Further reading
Rutherford J. Gettens; Hermann Khn; W. T. Chase (1967). “Identification of the Materials of Paintings: Lead White”. Studies in Conservation 12 (4): 125139.. http://links.jstor.org/sici?sici=0039-3630%28196711%2912%3A4%3C125%3ALW%3E2.0.CO%3B2-0.
External links
Case Studies in Environmental Medicine (CSEM): Lead Toxicity
Lead in Paint, Dust, and Soil
National Pollutant Inventory (Australia) – Lead and Lead Compounds Fact Sheet
Manufacture of White Lead Pigment
The Secret History of Lead: Special Report- Nation Magazine
Lead Paint Safety: EPA’s Field Guide for Painting, Home Maintenance, and Renovation Work
National Survey of Lead and Allergens in Housing
An Annotated Bibliography of Works concerning Paint and Colour prepared by Patrick Baty. Many early sources on lead paint are listed and discussed.
Some Myths concerning Lead Paint
Information for contractors working on pre-1978 homes and new EPA regulations
Categories: Toxicology | Lead | Paints | Painting and the environmentHidden categories: All articles with unsourced statements | Articles with unsourced statements from February 2008
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