Lead paint
[1] Lead is added to paint to accelerate drying, increase durability, maintain a fresh appearance, and resist moisture that causes corrosion.
[3] 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.
Hundreds or thousands of earthenware pots containing vinegar and lead were embedded in a layer of either tan bark or cow dung.
[5] Despite the risks, the pigment was very popular with artists because of its density and opacity; a small amount could cover a large surface.
[19] 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.
[20] 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.
This act superseded and harmonized existing laws of the member states, many of which had banned lead paint years before.
[24] Furthermore, unlike the U.S., which implemented stricter rules in 2010, renovators in Hong Kong do not need to be certified when performing lead paint related works.
[25][26] A 2015 study found that over 31% of household paints in India (small brands manufactured by small and medium enterprises in India, with limited local reach and distribution) had lead concentration above 10,000 parts per million (ppm), which far exceeds the BIS standard of 90 ppm for lead in paint.
The cited reason was "to reduce the risk of lead poisoning in children who may ingest paint chips or peelings".
[35] 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.
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.
[37][38] While EPA and HUD have defined LBP as being 1.0 mg/cm2 (as measure by XRF) or 0.5% lead by dry weight (aka 5,000 ppm), some states and municipalities gone beyond this.
For example, New York City's Local Law 66 of 2019 defines LBP as 0.500 mg/cm2 (XRF) or 0.25% lead dry weight (2,500 ppm).
[40] 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.
Through authority vested in the United States Department of Housing and Urban Development (HUD), lead-based-paint removal by dry scraping, dry sanding, torching and burning, the use of heat guns over 1100°F, and machine-sanding / grinding without a HEPA-filtered vacuum or a HEPA filtered dust collection system, is prohibited, as these methods have been proven to produce significant amount of lead dust during renovation, remodeling and painting.
[42] At the end of any remodeling or repainting job, a dust test performed by an independent third-party professional is also required by HUD for "clearance".
Lead evaluations are done using a method called X-Ray fluorescence (XRF), which gives a result in 4–8 seconds with a 95% accuracy at the 2-sigma level.
[44] 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.
Lead white oil paints are still produced and in use by artists who prefer their unique handling, mixing, and structural qualities.
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.
