Lead paint

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Lead paint or lead-based paint is paint containing lead. As pigment, lead(II) chromate (PbCrO4, "chrome yellow"), Lead(II,IV) oxide, (Pb3O4, "red lead"), and lead(II) carbonate (PbCO3, "white lead") are the most common forms.[1] Lead is added to paint to accelerate drying, increase durability, maintain a fresh appearance, and resist moisture that causes corrosion. It is one of the main health and environmental hazards associated with paint. Alternatives such as water-based, lead-free traffic paint are readily available, and many states and federal agencies have changed their purchasing contracts to buy these instead.[citation needed]

In some countries, lead continues to be added to paint intended for domestic use,[2] whereas countries such as the United States and the United Kingdom have regulations prohibiting this, although lead paint may still be found in older properties painted prior to the introduction of such regulations. Although lead has been banned from household paints in the United States since 1978, paint used in road markings may still contain it.

History[]

Lead white was being produced during the 4th century BC; the process is described by Pliny the Elder, Vitruvius and the ancient Greek author Theophrastus.

The traditional method of making the pigment was called the stack process. Hundreds or thousands of earthenware pots containing vinegar and lead were embedded in a layer of either tan bark or cow dung. The pots were designed so that the vinegar and lead were in separate compartments, but the lead was in contact with the vapor of the vinegar. The lead was usually coiled into a spiral, and placed on a ledge inside the pot. The pot was loosely covered with a grid of lead, which allowed the carbon dioxide formed by the fermentation of the tan bark or the dung to circulate in the pot. Each layer of pots was covered by a new layer of tan, then another layer of pots. The heat created by the fermentation, acetic acid vapor and carbon dioxide within the stack did their work, and within a month the lead coils were covered with a crust of white lead. This crust was separated from the lead, washed and ground for pigment. This was an extremely dangerous process for the workmen. Medieval texts warned of the danger of "apoplexy, epilepsy, and paralysis" from working with lead white.[3]

In 1786, Benjamin Franklin wrote a letter warning a friend about the hazards of lead and lead paint, which he considered well-established.[4] Despite the risks, the pigment was very popular with artists because of its density and opacity; a small amount could cover a large surface. It was widely used by artists until the 19th century, when it was replaced by zinc white and titanium white.[5]

The dangers of lead paint were considered well-established by the beginning of the 20th century. In the July 1904 edition of its monthly publication, Sherwin-Williams reported the dangers of paint containing lead, noting that a French expert had deemed lead paint "poisonous in a large degree, both for the workmen and for the inhabitants of a house painted with lead colors".[6] As early as 1886, German health laws prohibited women and children from working in factories processing lead paint and lead sugar.[7]

The League of Nations began efforts to ban lead paint in 1921.[8][9]

Toxicity[]

Lead paint can crack and form flakes, which then contaminate the surrounding environment.

Lead paint is hazardous. It can cause nervous system damage, stunted growth, kidney damage, and delayed development.[10] It is dangerous to children because it tastes sweet, therefore encouraging children to put lead chips and toys with lead dust in their mouths. Lead paint can cause reproductive problems, including a decrease in sperm concentration in men.[11] Lead is also considered a likely carcinogen. High levels of exposure can be lethal.

Regulation[]

Canada[]

In Canada, regulations were first enacted under the Hazardous Products Act in 1976 that limited lead content of paints and other liquid coatings on furniture, household products, children's products, and exterior and interior surfaces of any building frequented by children to 0.5% by weight.[12] New regulations on surface coating materials, which came into force in 2005, further limit lead to its background level for both interior and exterior paints sold to consumers. Canadian paint manufacturers have been conforming to this background level in their interior and exterior consumer paints since 1991.[13] Nevertheless, a Canadian company, Dominion Colour Corporation, is "the largest manufacturer of lead-based paint pigments in the world" and has faced public criticism for obtaining permission from the European Chemicals Agency to continue to export lead chromate paints from its Dutch subsidiary to countries where its uses are not tightly regulated.[14][9]

European Union[]

Lead paint is banned in the European Union by the 2003 Restriction of Hazardous Substances Directive (RoHS), which forbids hazardous substances in consumer goods, including paint. This act superseded and harmonized existing laws of the member states, many of which had banned lead paint years before.

To protect the health of painters, France had passed in 1909 a law banning the use of paints containing lead for the painting of the interior and exterior of all buildings.[15]

India[]

Lead paint was not prohibited in India until 2016.[16][17] A 2015 study found that over 31% of household paints in India had lead concentration above 10,000 parts per million (ppm), which far exceeds the BIS standard of 90 ppm for lead in paint.[18] The Regulation on Lead Contents in Household and Decorative Paint Rules came into effect on November 1, 2017, according to which the paints should have lead less than 90 ppm and their label should say so.[19] But two years later, an analysis of 32 locally manufactured paint samples from nine states found lead content ranging from 10 ppm to 1,86,062 ppm, with 90% of samples having lead levels above 90 ppm.[20]

Philippines[]

The Philippines banned lead paint in 2013, but in 2017, 15% of the paint still was not certified.[21] The EcoWaste Coalition and the Philippine Association of Paint Manufacturers declared on 1 January 2020 that the Philippines has phased-out lead paint following the implementation of Department of Environment and Natural Resources (DENR) Administrative Order 2013–24, or the Chemical Control Order for Lead and Lead Compounds, which directed manufacturers of lead-containing paints for industrial uses to phase out such paints by 31 December 2019.[22]

South Africa[]

In South Africa, the Hazardous Substances Act of 2009 classifies lead as a hazardous substance and limits its use in paint to 600 parts per million (ppm). A proposed amendment will modify this to 90 ppm, thereby almost completely eradicating lead from paint. The amendment would also include all industrial paints, which were previously excluded.[23]

United States[]

EPA poster on protecting children from lead poisoning

The U.S. Consumer Product Safety Commission (CPSC) banned lead paint in 1977 in residential properties and public buildings (16 CFR 1303), along with toys and furniture containing lead paint. The cited reason was "to reduce the risk of lead poisoning in children who may ingest paint chips or peelings".[24] For manufacturers, the CPSC instituted the Consumer Product Safety Improvement Act of 2008, which changed the cap on lead content in paint from 0.06% to 0.009% starting 14 August 2009. In 2018 the State of Delaware banned the use of lead paint on outdoor structures.[25] Also, the Residential Lead-Based Paint Hazard Reduction Act (AKA the "Lead Paint Act") was created in order to ensure that the disclosure of any lead-based hazards in a building be discussed with potential buyers or renters of units.[26][27]

In April 2010 the U.S. Environmental Protection Agency (EPA) required that all renovators working in homes built before 1978 and disturbing more than six square feet of lead paint inside the home or 20 square feet outside the home be certified. EPA's Lead Renovation, Repair and Painting Rule (RRP Rule) lowers the risk of lead contamination from home renovation activities.[28] It requires that firms performing renovation, repair, and painting projects that disturb lead-based paint in homes, child care facilities and pre-schools (any child occupied facility) built before 1978 be certified by EPA and use certified renovators who are trained by EPA-approved training providers to follow lead-safe work practices.[29]

As of 2018, there are an estimated 37 million homes and apartments with lead paint in the United States.[30]

Lead paint in art[]

Oil paints[]

In art, white lead paint is known as "flake white" or "Cremnitz white". It is valued for the ease of handling and resilience the lead confers to oil paints. Lead white paint dries relatively quickly to form a strong, flexible paint film. Lead-based white is one of the oldest manufactured pigments. It was the only white pigment available to artists in appreciable quantities until the twentieth century, when zinc white and titanium white became available.[31] Industrially produced lead white, the typical pigment from the 19th century until its ban, was thought to be inferior to traditionally fabricated forms, which had larger "flake" particles that conferred ease of handling.

Titanium and zinc whites are far less toxic than lead white and have largely supplanted it in most fine arts applications. Safety regulations have also made lead white more expensive and difficult to obtain in some regions, such as the EU. Lead white oil paints are still produced and in use by artists who prefer their unique handling, mixing, and structural qualities.[31]

Flake white has various drawbacks, including a tendency to become transparent over time. It also blackens in the presence of certain atmospheric pollutants, although this can be reversed.

Water-based paints[]

Lead is not a traditional pigment in water media, as zinc is superior for works on paper, as is calcium hydroxide (slaked lime) for frescos. Lead-based paints, when used on paper, often cause the work to become discolored after long periods; the paint's lead carbonate reacts with hydrogen sulfide in the air and with acids, which often come from fingerprints.[32]

Substitutes[]

Titanium[]

Paint manufacturers have 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. Titanium dioxide is considered safe enough to use as a food coloring and in toothpaste. It is also a common ingredient in sunscreen. When used in paints today, it is often coated with silicon or aluminium oxides for durability. Titanium white has far greater opacity and tinting strength than lead white, and it can easily overpower most other pigments if not mixed carefully. Titanium white has been criticized for leading to "chalkiness" in mixtures, and for allegedly decreasing the permanence of organic pigments mixed with it due to its high refractive index.

Zinc[]

Zinc white is less opaque and weaker in tinting strength than either titanium white or lead white. It is commonly used to lighten mixtures subtly while maintaining transparency. Although zinc white is the standard white in watercolors, its structural soundness in oils has been debated. Zinc white dries slowly and creates a relatively inflexible paint film. Critics of the pigment argue that its use leads to excessive cracking and delamination, even when used sparingly.[33]

See also[]

References[]

  1. ^ Völz, Hans G.; et al. (2006). "Pigments, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a20_243.pub2. ISBN 3527306730..
  2. ^ "Lead-laden paint still widely sold around the world". Reuters. 25 August 2009.
  3. ^ Daniel V. Thompson, The Materials and Techniques of Medieval Painting, pp. 90–91.
  4. ^ Benjamin Franklin (18 June 2011). Nathan G. Goodman (ed.). The Ingenious Dr. Franklin: Selected Scientific Letters of Benjamin Franklin. ISBN 978-1258046989. Retrieved 20 July 2018.
  5. ^ Philip Ball (2000), Bright Earth, Art and the Invention of Colour, pg. 99.
  6. ^ Guenther, Richard (24 February 1904). "Dangers of White Lead". Hathitrust. Sherwin Williams Co. Retrieved 31 October 2014.
  7. ^ Ayaß, Wolfgang, ed. (1 January 1999). Quellensammlung zur Geschichte der deutschen Sozialpolitik 1867 bis 1914, II. Abteilung: Von der kaiserlichen Sozialbotschaft bis zu den Februarerlassen Wilhelms II. (1881-1890), 3. Band: Arbeiterschutz [Collection of Original Texts on the History of German Social Policy from 1867 through 1914, 2nd Series: from the Imperial Social Message Through the February Decrees of Wilhelm II (1881-1890), 3rd volume: Worker protection] (in German). Darmstadt: Wissenschaftliche Buchgesellschaft. ISBN 3-534-13440-0., sections 26 & 121
  8. ^ Frowein, Jochen A; Rüdiger, Wolfrum (2000). Max Planck Yearbook of United Nations Law. Martinus Nijhoff Publishers. ISBN 90-411-1403-3.
  9. ^ Jump up to: a b Gottesfeld, Perry (29 May 2013). "The West's toxic hypocrisy over lead paint". New Scientist. Retrieved 20 July 2018.
  10. ^ Agency for Toxic Substances and Disease Registry (August 2007). "ToxFAQs™ for Lead". Center for Disease Control.
  11. ^ Bonde, J. P.; Joffe, M.; Apostoli, P.; Dale, A.; Kiss, P.; Spano, M.; Caruso, F.; Giwercman, A.; Bisanti, L.; Porru, S.; Vanhoorne, M.; Comhaire, F.; Zschiesche, W. (April 2002). "Sperm count and chromatin structure in men exposed to inorganic lead: lowest adverse effect levels". Occupational and Environmental Medicine. PubMed. 59 (4): 234–242. doi:10.1136/oem.59.4.234. PMC 1740274. PMID 11934950.
  12. ^ "Some Commonly Asked Questions About Lead and Human Health". Ottawa, ON: Health Canada. 23 April 2009.
  13. ^ "Lead and Health". Health Canada. Archived from the original on 3 June 2013. Retrieved 3 June 2013.
  14. ^ Fowler, Jennifer (1 December 2015). "Toronto company's lead-based products a danger to world health, critics say". CBC News. Toronto, ON. Retrieved 20 April 2016.
  15. ^ "Bulletin de l'Inspection du Travail et de l'Hygiène Industrielle" (PDF). Inspection du Travail Page 172.
  16. ^ Datta, Aesha. "CPCB norms seek to cap lead content in paints at 90 ppm". The Hindu Business Line. Chennai. Retrieved 12 July 2020.
  17. ^ Aggarwal, Mayank (28 April 2016). "Govt proposes to ban household paint with high lead content". Mint. New Delhi. Retrieved 12 July 2020.
  18. ^ "Over 31 percent paints have alarming levels of lead: study". The Indian Express. Mumbai. 9 June 2015.
  19. ^ Vyawahare, Malavika (2 November 2017). "If your paint label doesn't say 'lead less than 90 ppm,' don't buy it". Hindustan Times. New Delhi.
  20. ^ Oppili, P (23 June 2020). "Tamil Nadu: Paints continue to have more lead than prescribed". The Times of India. Chennai.
  21. ^ Mogensen, Jackie Flynn (23 April 2018). "You'll Probably Never Save as Many Lives as This Guy Who Got the Philippines to Stop Using Lead Paint". Mother Jones. Retrieved 23 April 2018.
  22. ^ "Philippines Successfully Completes Phase-Out of All Lead-Containing Paints". Philippine Canadian Inquirer. 5 January 2020. Retrieved 6 January 2020.
  23. ^ Bulbulia, Tasneem. "Proposed amendment to legislation set to eliminate lead in paint". Engineering News. Retrieved 25 September 2018.
  24. ^ "CPSC Announces Final Ban on Lead-Containing Paint". US Consumer Product Safety Commission. 2 September 1977. Archived from the original on 19 August 2010.
  25. ^ State of Delaware, General Assembly (29 August 2018). "HB 456. An Act to Amend Titles 14, 16, 17, 26, and 29 of the Delaware Code Relating to the Use of Lead Paints on Outdoor Structures".
  26. ^ Bailey, Adam Leitman (7 November 2019). "Case Study: Whether a Title Company is Liable for Lead-Paint Contamination when Documents Indicated Lead Paint Existed". Washington, DC: American Land Title Association.
  27. ^ "The Lead Disclosure Rule". Washington, DC: US Department of Housing and Urban Development. Retrieved 8 February 2021.
  28. ^ "Lead Renovation, Repair and Painting Program Rules". Washington, DC: US Environmental Protection Agency (EPA). 14 September 2020.
  29. ^ "Lead Renovation, Repair and Painting Program". EPA. 15 October 2020.
  30. ^ Schmidt, Charles (21 March 2018). "America's Misguided War on Childhood Lead Exposures". Cambridge, MA: Undark.
  31. ^ Jump up to: a b Mayer, Ralph (1991). The artist's handbook of materials and techniques (5. ed., rev. and updated ed.). New York City: Viking. ISBN 0670837016.
  32. ^ 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.
  33. ^ "Zinc White – Problems in Oil Paint?". Natural Pigments LLC. Archived from the original on 6 February 2011.

Bibliography[]

External links[]

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