Lead paint

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. 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. Lead paint has been generally phased out of use due to the toxic nature of lead. Alternatives such as water-based, lead-free traffic paint are readily available. In many countries, lead paint remains permitted for domestic use, whereas in other jurisdictions, such as the United States, the United Kingdom and the European Union, there are regulations prohibiting or restricting its use. However, 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, it may still be found in road marking paint and artists' paints.

History White lead 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. In 1786, Benjamin Franklin wrote a letter warning a friend about the hazards of lead and lead paint, which he considered well-established. 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. 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". As early as 1886, German health laws prohibited women and children from working in factories processing lead paint and lead sugar. The League of Nations began efforts to ban lead paint in 1921.

Toxicity

Lead paint is hazardous. It can cause nervous system damage, stunted growth, kidney damage, and delayed development. It is associated with high violent crime rates. 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. Lead is also considered a likely carcinogen. High levels of exposure can be lethal. Several methods exist to test for the presence of lead in paint, including analysis in a laboratory and various at-home tests, with varying efficacies. Spot test kits for lead are sold to consumers, but were found by one study to have high error rates.

Regulation As of 30 December 2021, these are the places with confirmed lead paint laws according to the WHO Global Health Observatory Database:

Africa

South Africa In South Africa, the Hazardous Substances Act of 2009 classified lead as a hazardous substance and limited its use in paint to 600 parts per million (ppm). An amendment taking effect in May 2025 modified this to 90 ppm. The amendment also included all industrial paints, which were previously excluded. From May 2026, all packaging must also comply, displaying the text "Conforms with the South African legal lead limit of 90 ppm or less".

Elsewhere in Africa As of January 2026, Burundi, Democratic Republic Congo, Niger, Sierra Leone and Zimbabwe have all made progress towards a regulatory framework on lead reduction.

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. 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. 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.

China New regulation effective from 1 December 2020 updates an older lead paint standard introduced in the 1980s, which measured soluble lead in products instead of total lead. Measuring soluble lead is considered to be a less accurate method for measuring the amount of lead paint exposure in children. The new standards set a 90 ppm total lead limit for woodware coatings and architectural wall coatings. For vehicle and industrial coatings the new total lead limit is 1,000 ppm.

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