Hubbry Logo
Paris greenParis greenMain
Open search
Paris green
Community hub
Paris green
logo
7 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Paris green
Paris green
Paris green
View on Wikipedia
from Wikipedia

Paris green
Cu2(CH3CO2)(As3O6)
Names
Other names
C.I. pigment green 21, emerald green, Schweinfurt green, imperial green, Vienna green, Mitis green, Veronese green[1]
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.125.242 Edit this at Wikidata
EC Number
  • 601-658-7
UNII
UN number 1585
  • InChI=1S/2C2H4O2.6AsHO2.4Cu/c2*1-2(3)4;6*2-1-3;;;;/h2*1H3,(H,3,4);6*(H,2,3);;;;/q;;;;;;;;4*+2/p-8
    Key: HTSABAUNNZLCMN-UHFFFAOYSA-F
  • CC(=O)[O-].CC(=O)[O-].[O-][As]=O.[O-][As]=O.[O-][As]=O.[O-][As]=O.[O-][As]=O.[O-][As]=O.[Cu+2].[Cu+2].[Cu+2].[Cu+2]
  • CC(=O)[O-].CC(=O)[O-].[O-][As]0O[As]([O-])O[As]([O-])O0.[O-][As]0O[As]([O-])O[As]([O-])O0.[Cu+2].[Cu+2].[Cu+2].[Cu+2]
Properties
Cu(C2H3O2)2·3Cu(AsO2)2
Molar mass 1013.79444 g⋅mol−1
Appearance Emerald green crystalline powder
Density >1.1 g/cm3 (20 °C (68 °F; 293 K))
Melting point > 345 °C (653 °F; 618 K)
Boiling point decomposes
insoluble
Hazards
GHS labelling:[2]
GHS06: ToxicGHS09: Environmental hazard
Danger
H300, H313, H331, H411
P261, P264, P273, P280, P301+P310, P304+P340
NFPA 704 (fire diamond)
[3]
NFPA 704 four-colored diamondHealth (blue): no hazard codeFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
Lethal dose or concentration (LD, LC):
22 mg/kg[citation needed]
NIOSH (US health exposure limits):[4]
PEL (Permissible)
 TWA 0.01 mg/m3 (as As)
REL (Recommended)
 0.002 mg/m3 (15-minute, as As)
IDLH (Immediate danger)
 5 mg/m3 (as As)]
Safety data sheet (SDS) Toronto Research Chemicals SDS[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Paris green
 
About these coordinates     Color coordinates
Hex triplet#50C878
sRGBB (r, g, b)(80, 200, 120)
HSV (h, s, v)(140°, 60%, 78%)
CIELChuv (L, C, h)(72, 71, 137°)
SourceMaerz and Paul[a][better source needed]
ISCC–NBS descriptorVivid yellowish green
B: Normalized to [0–255] (byte)

Paris green (copper(II) acetate triarsenite or copper(II) acetoarsenite) is an arsenic- and copper-containing pigment. It is an emerald-green crystalline powder that is also known as Mitis green, Schweinfurt green, Sattler green, emerald, Vienna green, Emperor green or Mountain green. It is highly toxic[5] and has thus also been used as a rodenticide and insecticide.[6] Its formula is Cu(C2H3O2)2·3Cu(AsO2)2.[7]

It was manufactured in 1814 to be a pigment to make a vibrant green paint, and was used by many notable painters in the 19th century. The color of Paris green is said to range from a pale blue green when very finely ground, to a deeper green when coarsely ground. Due to the presence of arsenic, the pigment is extremely toxic. In paintings, the color can degrade quickly.

Preparation and structure

[edit]

Paris green may be prepared by combining copper(II) acetate and arsenic trioxide.[8] The structure was confirmed by X-ray crystallography.[7]

A subunit of the Cu(C2H3O2)2·3Cu(AsO2)2 framework, highlighting the As3O3−6 ligand. Color code: Cu = blue, As = large gray, C = gray, O = red.

History

[edit]

In 1814, Paris green was invented by paint manufacturers Wilhelm Sattler and Friedrich Russ, in Schweinfurt, Germany for the Wilhelm Dye and White Lead Company. They were attempting to produce a more stable pigment than Scheele's green, seeking to make a green that was less susceptible to darkening around sulfides. In 1822, the recipe for emerald green was published by Justus von Liebig and André Braconnot.[9]

In 1867, the pigment was named Paris green and was officially recognized as the first chemical insecticide in the world. Because of its arsenic content, the pigment was dangerous and toxic to manufacture, often resulting in factory poisonings.[10][11] At the time, emerald green was praised as a more durable and vibrant substitute for Scheele's green, even though it would later prove to degrade quickly and react with other manufactured paints.[citation needed]

Pigment

[edit]

In paintings, the pigment produces a rich, dark green with an undertone of blue. In comparison, Scheele's green is more yellow, and therefore, more lime-green.[12]: 220  Paris green became popular in the 19th century because of its brilliant color.[12]: 223  It was also called emerald green because of its resemblance to the gemstone's deep color.

Permanence

[edit]
Can of Paris green pigment by Sherwin-Williams Co.

The pigment has a tendency to darken and turn brown. The issue was already apparent in the 19th century. In a 1888 study, watercolors with the pigment were shown to darken and turn brown when exposed to natural light and air. Experiments at the turn of the 20th century gave mixed results. Some found that the Paris green degraded slightly while other sources said the pigment was weatherproof.[12]: 227  This discrepancy could be due to the fact that each experiment used a different brand of Paris green.[12]: 228 

Paris green in Descente des Vaches by Théodore Rousseau has changed significantly.[13]

[edit]

Similar natural compounds are the minerals chalcophyllite Cu18Al2(AsO4)3(SO4)3(OH)27·36H2O, conichalcite CaCu(AsO4)(OH), cornubite Cu5(AsO4)2(OH)4·H2O, cornwallite Cu5(AsO4)2(OH)4·H2O, and liroconite Cu2Al(AsO4)(OH)4·4H2O. These minerals range in color from greenish blue to slightly yellowish green.[citation needed]

Scheele's green is a chemically simpler, less brilliant, and less permanent, copper-arsenic pigment used for a rather short time before Paris green was first prepared, which was approximately 1814. It was popular as a wallpaper pigment and would degrade, with moisture and molds, to arsine gas.[citation needed] Paris green was used in wallpaper to some extent and may have degraded similarly.[14] Both pigments were once used in printing ink formulations.[citation needed]

The ancient Romans used one of them, possibly conichalcite, as a green pigment. The Paris green paint used by the Impressionists is said to have been composed of relatively coarse particles. Later, the chemical was produced with increasingly small grinds and without carefully removing impurities. Its permanence suffered. It is likely that it was ground more finely for use in watercolors and inks.[citation needed]

Uses

[edit]

Painting

[edit]

Paris green was widely used by 19th-century artists. It is present in several paintings by Claude Monet and Paul Gauguin, who found its color difficult to replicate with natural materials.[12]: 256 [15]

Vincent van Gogh, Self-Portrait (Dedicated to Paul Gauguin), September, 1888. Note the vivid background and undercoat of Paris green.
Georges Seurat, A Sunday on la Grande Jatte: an example of a neo-Impressionist work using emerald green[16]

Insecticide

[edit]

In 1867, farmers in Illinois and Indiana found that Paris green was effective against the Colorado potato beetle, an aggressive agricultural pest. Despite concerns regarding the safety of using arsenic compounds on food crops, Paris green became the preferred method for controlling the beetle. By the 1880s, Paris green had become the first widespread use of a chemical insecticide in the world.[17] It was also used widely in the Americas to control the tobacco budworm, Heliothis virescens.[18] To kill codling moth, it was mixed with lime and sprayed on fruit trees.[19]

Paris green was heavily sprayed by airplane in Italy, Sardinia, and Corsica during 1944 and in Italy in 1945 to control malaria.[20] It was once used to kill rats in Parisian sewers, which is how it acquired its common name.[21]

However, the manufacturing of the insecticide caused many health complications for factory workers, and in certain cases was lethal.[22]

Illustrations of Paris green
  • Mixing "Paris green" and road dust preparatory to dusting streams and breeding places of mosquitoes during World War II
    Mixing "Paris green" and road dust preparatory to dusting streams and breeding places of mosquitoes during World War II
  • Use as insecticide, poster issued by US Public Health Service
    Use as insecticide, poster issued by US Public Health Service

Bookbindings

[edit]

Throughout the 19th century, Paris green and similar arsenic pigments were used in books, particularly on bookcloth coverings, textblock edges, decorative labels and onlays, and in printed or manual illustrations. The colorant is particularly prevalent in bookbindings from the 1850s and 1860s published in Germany, England, France, and the United States. Use of arsenic-containing pigments waned in the later part of the 19th-century with heightened awareness of their toxicity and the availability of less toxic chromium- and cobalt-based alternatives. Since February 2024, several German libraries have started to block public access to their stock of 19th century books, to check for the degree of poisoning.[23][24] The Poison Book Project has cataloged books with these bindings.[25]

Wallpaper

[edit]

Paris green became a popular paint in mass-produced wallpaper, which is believed to have shortened lifespans.[26] Wallpaper swatches from this era have been preserved in the book Shadows from the Walls of Death.

Fireworks

[edit]

The color pigment is also used by various historical formulas in fireworks to create blue flame effects. However the commercial use is precluded due to the high toxicity.[27]

See also

[edit]

Footnotes

[edit]

References

[edit]

Further reading

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Paris green

View on Grokipedia
from Grokipedia
Paris green, also known as emerald green or green, is a highly toxic synthetic with the C₄H₆As₆Cu₄O₁₆, consisting of (II) acetoarsenite and containing approximately 43% by weight. Invented in 1814 in , , by paint manufacturers Wilhelm Sattler and Friedrich Russ while attempting to improve upon the earlier , it quickly gained popularity for its vibrant, stable emerald hue that resisted fading in light. The pigment's name is believed to derive from a 1830s incident in , , where several people died after ingesting candy coated with the color, though it became a staple in the fashion and decorative arts industries during the 19th century. It was extensively applied in oil and watercolor paints, wallpapers, textiles, and even bookbindings, contributing to the vivid greens seen in Impressionist artworks and Victorian interiors. Beyond aesthetics, Paris green was repurposed as one of the first synthetic insecticides starting in the 1860s, particularly effective against the and other agricultural pests, remaining in use until the mid-20th century when safer alternatives emerged. Due to its arsenic content, Paris green poses severe health risks, including acute through , , or contact, with a probable oral of 5-50 mg/kg (approximately 0.35-3.5 g for a 70 kg adult); chronic exposure can lead to lesions, cancers, and organ damage, classifying it as a human by the International Agency for Research on Cancer. Its toxicity contributed to historical incidents of illness and death, such as from -laden wallpapers releasing vapors in damp conditions, prompting regulations that phased out its use in consumer products by the early . Today, it is no longer registered for agricultural use and is primarily of historical and conservational interest, with ongoing research into its presence in museum artifacts.

Composition and Preparation

Chemical Formula and Structure

Paris green, chemically known as copper(II) acetoarsenite, has the empirical formula \ceCu(C2H3O2)2⋅3Cu(AsO2)2\ce{Cu(C2H3O2)2 \cdot 3Cu(AsO2)2}, which corresponds to the molecular formula \ceC4H6As6Cu4O16\ce{C4H6As6Cu4O16}. This composition reflects a coordination complex involving four copper atoms, six arsenic atoms, and a combination of acetate and arsenite moieties. The molecular structure consists of copper(II) ions (\ceCu2+\ce{Cu^2+}) coordinated primarily through oxygen atoms from ligands (\ceC2H3O2−\ce{C2H3O2^-}) and groups (\ceAsO2−\ce{AsO2^-}), forming a polymeric network that contributes to its stability as a solid. In a typical representation, the two units bridge copper centers, while the three diarsenite units link additional ions, resulting in an extended ionic lattice. This arrangement is responsible for the compound's characteristic emerald-green color, arising from d-d transitions in the centers influenced by the ligand field. Paris green manifests as an emerald-green crystalline powder, often with trace content, and its crystals exhibit low in due to the strong ionic interactions within the lattice. Historical commercial formulations occasionally incorporated impurities, such as , which could alter the precise but did not fundamentally change the core acetoarsenite structure.

Synthesis Methods

The original synthesis of Paris green, developed in 1814 by Wilhelm Sattler and Friedrich Russ in Schweinfurt, Germany, involved reacting a solution of sodium arsenite with copper(II) sulfate to precipitate an intermediate copper arsenite, followed by the addition of sodium acetate or acetic acid to form the stable copper acetoarsenite complex. This wet chemistry approach yielded a vibrant emerald-green powder after filtration, washing, and drying, marking an improvement over the less stable Scheele's green by incorporating the acetate ligand for enhanced color brilliance and lightfastness. In industrial production, which became widespread in the 19th century, the pigment was prepared by boiling verdigris (copper(II) acetate) with arsenic trioxide (white arsenic) in water or dilute acetic acid, typically at temperatures of 80–100°C for several hours to facilitate the reaction and precipitate the product. The resulting green sediment was then filtered, washed to remove excess reagents, and dried, often achieving yields around 80% based on the limiting reactant, though the process required careful control to minimize side products. Historical batches frequently suffered from purity issues, including contamination by excess arsenious oxide, which could comprise up to several percent of the final product and affect its stability. Due to its high arsenic content and associated health risks, commercial synthesis of Paris green was discontinued in the early , with production ceasing entirely by the in most regions. Modern approaches are limited to rare recreations for or conservation purposes, employing controlled environments and safer handling of precursors like salts and arsenites to replicate historical methods without scaling for commercial use.

History

Invention and Early Development

Paris green, also known as emerald green or Schweinfurt green, was invented in 1814 by German chemists Wilhelm Sattler and Friedrich in , (now ), as part of the Wilhelm Dye and Company's efforts to develop a superior . This synthetic acetoarsenite emerged as a brighter and more stable alternative to , a arsenite discovered in 1775 that tended to fade or shift to a yellowish hue over time. The new pigment's vivid emerald tone addressed the limitations of earlier greens, offering enhanced vibrancy for artistic and decorative applications. The invention occurred amid a surge in demand for bold, synthetic colors in post-Napoleonic , where the end of the in 1815 spurred economic recovery, expanded trade, and a renewed interest in , , and production. Initially developed for use as a in paints, wallpapers, and textiles, Paris green met the era's craving for luxurious, eye-catching hues that natural pigments like could not consistently provide at scale. Sattler and Russ's process involved reacting (copper ) with in acetic acid, yielding a brilliant green powder that quickly gained traction in European dye works despite its undisclosed formula at the time. Early production began on a small commercial scale in shortly after 1814, with the pigment's secrecy maintained until chemists and André Dumas analyzed and replicated it in 1822, facilitating wider adoption. Although originating in , the name "Paris green" arose from its rapid refinement and popularity among Parisian dyers and manufacturers by the early 1820s, where it was prized for coloring silks, gowns, and decorative items in the burgeoning industry. This French association overshadowed its Bavarian roots, establishing Paris green as a staple in 19th-century before its toxicity became widely recognized.

Commercialization in the 19th Century

Following its by Wilhelm Sattler and Friedrich in 1814, Paris green experienced a boom in the , marked by in at the Wilhelm Dye and Company in and in , with exports expanding to the and the . The Schweinfurt facility, under Sattler, became a key exporter of large quantities of the , known locally as Schweinfurter Grün, fueling its integration into European and transatlantic markets. In , overall arsenic compound production, including for Paris green, reached approximately 286,000 kg per year around 1840, reflecting the pigment's economic significance. Key market drivers were the surging needs of wallpaper manufacturers and artists for a brilliant, stable , with the typically priced at approximately 1.5 francs (or $0.30) per pound in the . networks relied on shipments from ports like , integrating Paris green into the broader 19th-century color revolution that paralleled the emergence of synthetic dyes. By the 1870s, Paris green dominated as the preeminent green in commercial applications across and . Nonetheless, early concerns surfaced in journals during the 1860s, with reports highlighting health risks from exposure in production and use environments.

Physical and Chemical Properties

Appearance and Solubility

Paris green is an emerald-green crystalline powder or fine solid, often described as bright and vivid in hue, with a characteristic luster that contributes to its appeal as a pigment . This appearance stems from its composition, where the arsenic content imparts the intense green coloration through coordination with ions. When prepared for artistic or industrial use, it is ground into particles typically around 10 microns in size, enabling effective light scattering and providing high opacity in applications. In terms of solubility, Paris green is insoluble in and alcohol, rendering it stable in many aqueous and alcoholic media. It exhibits solubility in dilute acids, such as acetic acid, but decomposes in stronger acids or bases, releasing compounds. Physically, the has a specific gravity of 3.27 and does not melt upon heating; instead, it decomposes above 345°C.

Stability and Reactivity

Paris green, or copper acetoarsenite, demonstrates relative stability under dry, neutral, and ambient conditions, remaining largely unaffected by exposure to air or light. It is considered lightfast, resisting fading, but can react in certain binding media. However, it exhibits significant reactivity with environmental factors such as , temperature, , and certain chemicals, leading to and release of hazardous byproducts. In the presence of , Paris green can undergo degradation, particularly in moist or reactive media such as oil paints, resulting in oxidation of its component and darkening to brown tones; it remains more stable in thoroughly dry conditions. The in Paris green exists primarily in the +3 , which is susceptible to conversion to the +5 state through oxidation processes, thereby modifying its reactivity and toxicity profile. Thermal reactivity is pronounced, with decomposition occurring above 345°C and the emission of highly toxic arsenic fumes or volatile arsenic oxide during heating or fires. Additionally, when heated in the presence of acids or exposed to acid fumes, it releases highly toxic arsenic oxide fumes. In damp environments, similar reactions can occur if reducing conditions are present, such as from molds, exacerbating the release of arsine gas (AsH₃). Regarding pH effects, Paris green is stable in neutral media but unstable in both acidic and alkaline solutions. In acidic conditions, it dissolves and decomposes, liberating arsenic-containing gases. In alkaline solutions, it hydrolyzes, breaking down into and compounds. This instability extends to reactions with , where it forms insoluble precipitates. Overall, these reactivities underscore the compound's weak oxidizing and reducing powers, necessitating careful handling to prevent unintended environmental or health risks.

Pigment Characteristics

Color Properties and Permanence

Paris green, also known as emerald green or copper acetoarsenite (CI Pigment Green 21), displays a vivid emerald hue with high chroma and saturation, characterized by a bright, slightly bluish tone that approximates RGB values of (80, 200, 120). This intense coloration stems from its , providing a pure that was prized for its brilliance in 19th-century . The pigment exhibits opacity with moderate to strong tinting strength, achieving effective at loadings of approximately 10-15% in oil or other binding media, allowing artists to cover substrates efficiently without excessive material use. In mixing, Paris green demonstrates versatile behavior typical of copper-based greens; it shifts toward olive tones when combined with yellow pigments like cadmium yellow, while blending with blues such as produces teal-like shades. In oil media, it can be applied as transparent glazes, leveraging its semi-transparency to create luminous layers without losing vibrancy. Regarding permanence, Paris green receives a rating equivalent to ASTM II (Very Good), though it exhibits moderate instability under prolonged exposure. It fades in sunlight primarily through the volatilization and transformation of components into (a ), alongside formation of carboxylates, resulting in desaturation and loss of tinting strength over time. The pigment shows greater stability in modern acrylic media due to the neutral and encapsulation, but it is unsuitable for techniques, where alkaline lime environments accelerate decomposition. Aging effects further compromise its longevity; exposure to sulfurous atmospheres, such as those from industrial pollution or in the air, causes blackening via formation of copper sulfides, dulling the once-vibrant to a darkened . Case studies from 19th-century canvases illustrate these issues: in Théodore Rousseau's Descente des vaches (1834–1835), originally bright areas containing Paris green degraded rapidly in to brownish tones within decades, attributed to interactions with free fatty acids forming soaps and , altering the artwork's intended coloration. Similar degradation has been observed in other historical paintings, where emerald green layers exhibit migration of arsenic compounds and color shifts under environmental stress. Scheele's green, invented in 1775 by Swedish chemist , served as an early precursor to Paris green and consists of copper arsenite with the formula CuHAsO₃. This pigment produces a more yellowish hue compared to the vivid emerald tone of Paris green and exhibits lower stability, particularly in the presence of compounds, where it can darken or produce toxic gas. Its relative instability and tendency to degrade under light or humid conditions limited its long-term use, though it was widely adopted in the late for wallpapers and textiles before being largely supplanted by more durable alternatives. Paris green is also known by several other names, including emerald green, green, and green, all referring to the same acetoarsenite with the approximate Cu(CH₃COO)₂ · 3Cu(AsO₂)₂. These synonyms arose from its places of production and use, such as , , and , but do not indicate compositional variants. Compared to , Paris green offered improved opacity, brightness, and resistance to fading, making it more suitable for a wider range of applications despite sharing the same arsenic-based . Differences in among arsenic greens—higher in Scheele's green—affect exposure risks, with Paris green being less prone to leaching in dry conditions. Overall, Paris green distinguished itself from precursors like through its acetoarsenite structure, providing greater resistance to environmental degradation than simpler arsenites, while all shared comparable profiles rooted in their copper-arsenic composition.

Uses

In Art and Painting

Paris green, also known as emerald green, emerged as a highly prized in 19th-century fine arts for its intense, vibrant hue that captured the luminosity of natural foliage and landscapes. Artists valued its transparency and brilliance, which allowed for dynamic layering and optical effects in paintings, particularly during the Impressionist and Pre-Raphaelite movements. Its adoption marked a shift toward synthetic pigments that offered unprecedented color intensity compared to earlier natural greens like or . Impressionist painters, such as , employed Paris green in their works during the mid-to-late 19th century to depict verdant scenes with vivid realism. used the pigment in earlier paintings, such as Bathers at (1869), but transitioned to more stable alternatives like for his later series. Pre-Raphaelite artists also integrated Paris green into their detailed, naturalistic compositions, often mixing it with to enhance stability and achieve subtle tonal variations. incorporated the pigment in works emphasizing lush, symbolic vegetation, aligning with the movement's embrace of synthetic colors introduced in the mid-19th century. similarly utilized it in underlayers for foliage, as seen in The and (1861), where emerald green was used to underpaint flesh tones and toned down for realistic effects, demonstrating its versatility in and techniques. Technically, the pigment was preferred in media for glazing applications due to its transparency, enabling thin veils of color over underpaintings to build luminosity; historical formulations typically involved a pigment-to-binder ratio of around 20-30% to balance opacity and flow without compromising adhesion. By the early 1900s, Paris green's use in had largely declined, phased out in favor of safer, more stable alternatives like chrome greens and , amid growing awareness of its content and instability in certain mixtures. Modern conservation efforts face challenges from its sensitivity to light and environmental factors, necessitating UV filtering in display cases to prevent degradation; has proven invaluable in revealing arsenic layers in historical paintings, aiding non-invasive authentication and restoration.

As an Insecticide

Paris green, an emerald-green arsenical compound known chemically as copper acetoarsenite, was first employed as an insecticide in the United States during the 1860s to combat the (Leptinotarsa decemlineata), a devastating pest that threatened crops across the Midwest. Introduced in 1865, it marked the beginning of broad-spectrum chemical , with farmers dusting or spraying the directly onto foliage to target the beetle's larvae and adults during outbreaks. This application helped avert widespread crop losses, as the beetle had rapidly spread from its native Rocky Mountain habitat to eastern farmlands, destroying fields in states like New York and by the early 1870s. As a stomach poison, Paris green proved highly effective against chewing insects like the , which ingest the toxic after feeding on treated leaves, leading to and death within hours to days. However, it was largely ineffective against contact pests with piercing-sucking mouthparts, such as , due to its reliance on ingestion rather than direct absorption through the . For optimal results and to minimize —such as leaf burn—Paris green was commonly mixed with hydrated lime at ratios of 1:10 to 1:20 before application, either as a for dry conditions or suspended in for spraying on fields. Its use peaked from the through the 1910s, enabling farmers to protect yields during severe infestations and establishing it as a cornerstone of early agricultural pest management. The adoption of Paris green extended globally, with French grape growers introducing it in the 1870s to control vineyard pests amid phylloxera outbreaks and other insect threats. In Australia, it was deployed against locust swarms, including the Australian plague locust (Chortoicetes terminifera), through baiting and dusting in the late 19th and early 20th centuries to curb agricultural damage during plagues. By the early 1900s, U.S. usage alone reached approximately 4 million pounds (about 1,800 metric tons) annually, reflecting surging production to meet demand for crop protection.

In Decorative Arts and Other Applications

Paris green, an emerald-hued arsenic-copper pigment invented in 1814, found widespread application in 19th-century decorative arts beyond fine painting, particularly in household and consumer goods where its vibrant color enhanced aesthetic appeal. In wallpaper production during the 1870s to 1890s, Paris green—often marketed as "Napoleon green"—was extensively incorporated into printed designs, with a typical Victorian parlor potentially containing up to four pounds of arsenic from the pigment. In damp environments, the compound's volatility released toxic arsenic vapors, leading to "green wallpaper poisoning" characterized by respiratory distress and systemic symptoms in occupants. For bookbindings, Victorian-era cloth covers on novels and other volumes from the 1880s onward frequently employed Paris green, known commercially as emerald green, to achieve a striking green finish on case bindings. Arsenic from the pigment could leach during handling, causing skin irritation and illnesses among binders, librarians, and readers who came into prolonged contact with the materials. In , Paris green contributed to green flames through the combustion of its copper-arsenic components, serving as a key ingredient in 19th-century compositions for vibrant displays. Its use persisted into the era despite toxicity concerns, often mixed with oxidizers like to enhance color intensity. Other decorative uses peaked in the with Paris green in toy paints, imparting bright colors to children's playthings, and as a for fabrics, including silks that featured the shade in gowns and accessories for its luxurious vibrancy. These exemplified the pigment's role in everyday consumer crafts before health risks curtailed its popularity.

Toxicity and Health Effects

Mechanisms of Arsenic Poisoning

Paris green, or copper acetoarsenite, exerts its toxicity primarily through its content, which enters the body via multiple absorption routes. The primary pathways include , of particles, and dermal contact, particularly from handling the or exposure to arsenic-containing wallpapers where absorption can occur through . is significant for fine dusts generated during pigment preparation or application, while dermal uptake is less efficient than ingestion or inhalation (such as of dust or mold-released arsine gas) but notable in prolonged contact scenarios. For related arsenic pigments such as Scheele's green (copper hydrogen arsenite, CuHAsO₃), occupational skin contact often led to chronic poisoning, with symptoms including skin lesions, ulcers, gastrointestinal distress, and systemic effects; prolonged exposure could be lethal, but acute lethality from skin contact alone was rare and typically required heavy, repeated exposure. Once absorbed, undergoes primarily in the liver, where it binds to sulfhydryl groups on proteins, disrupting enzymatic functions critical for . This binding inhibits key enzymes such as , which is essential for converting pyruvate to in the , leading to impaired energy production and accumulation of toxic intermediates. Additionally, inorganic is methylated via arsenite methyltransferase to form monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), with typical urinary excretion profiles showing 10-30% unchanged inorganic , 10-20% MMA, and 60-80% DMA; these metabolites can retain toxicity, particularly the trivalent forms. Acute exposure to arsenic from Paris green manifests as severe gastrointestinal distress, including , , , and profuse often described as rice-water stools due to their watery, rice-like appearance. These symptoms progress to , imbalances, and cardiovascular collapse, potentially leading to multi-organ failure if untreated. The estimated oral LD50 for Paris green in rats is 22 mg/kg. Human data are limited, but the minimal for inorganic arsenic equivalents is approximately 1-3 mg/kg body weight, with survival possible at higher levels with treatment. Chronic exposure results in characterized by numbness, tingling, and weakness in extremities, alongside skin lesions such as (thickened, hardened skin patches) and . Under certain degradation conditions, such as in damp environments with mold, Paris green can release trimethylarsine gas ((CH3)3As), known as Gosio gas, which contributes to chronic poisoning symptoms including and respiratory distress.

Historical Cases of Exposure

During the late , Paris green, an arsenic-based used in wallpapers, was implicated in numerous cases of chronic in the , particularly in humid homes where mold triggered the release of toxic vapors known as Gosio gas. A notable incident occurred in 1862 in , where children died after tearing and licking strips of arsenic-laden green wallpaper, highlighting the acute risks to vulnerable populations. By the 1890s, as awareness grew, production of such wallpapers declined sharply, but earlier epidemics contributed to concerns, with symptoms including , skin lesions, and respiratory distress mirroring broader mechanisms. These events spurred growing public awareness of risks in consumer products. Similar occupational poisonings occurred with predecessor pigments such as Scheele's green (copper hydrogen arsenite), an earlier arsenic-based pigment. In 1861, 19-year-old artificial flower maker Matilda Scheurer died from chronic arsenic poisoning after prolonged exposure while dusting artificial leaves and fabrics with the pigment, resulting in significant skin contact and inhalation of dust. Symptoms included vomiting green liquid, green discoloration of the eyes and nails, and autopsy findings confirmed arsenic accumulation in her stomach, liver, lungs, and other organs. Other 19th-century reports described seamstresses and workers suffering "wretched" green-stained fingers, skin lesions, and occasional fatalities from handling dyed fabrics or pigments. Artists handling Paris green in paints faced significant exposure risks, with posthumous analyses suggesting possible links to health issues among 19th-century painters. For instance, Vincent van Gogh's documented symptoms—chronic , neuropathy, and episodes of mental instability—have been attributed by some researchers to repeated contact with pigments like Paris green during his prolific use of vibrant greens in works such as his sunflower series. In the early 1900s, factory workers in dye plants producing Paris green experienced outbreaks of , including and ulcers, underscoring occupational hazards in pigment manufacturing. Agricultural use of Paris green as an in the 1870s United States led to accidental exposures on farms, particularly during potato crop sprays against the . Farmers reported acute from inhaling dust or ingesting residues, while children faced fatalities from mishandling the powder stored in households, as it was readily accessible and mistaken for non-toxic substances. These incidents highlighted the dangers of unregulated , with cases often involving gastrointestinal distress and convulsions in affected individuals. Medical recognition of Paris green-related poisonings advanced in the 1860s through forensic analyses, notably by Italian chemist Francesco Selmi, who developed methods to detect in autopsies by distinguishing it from cadaveric alkaloids like ptomaines. Selmi's 1874 discovery of the first ptomaine enabled more accurate identification of exogenous sources, such as pigments, in suspicious deaths. These advancements, building on earlier tests like James Marsh's detection method, facilitated 1890s public awareness campaigns in and the , emphasizing the need for safer alternatives in consumer goods. By the late , texts like E.S. Wood's 1885 "Arsenic as a Domestic " documented and cases, spurring epidemiological scrutiny.

Regulation and Legacy

Bans and Restrictions

The phase-out of Paris green began in the early with initial regulatory warnings in both the and the . In the , the of 1906 prohibited the interstate sale of adulterated or misbranded foods and drugs, effectively restricting the use of arsenic-based pigments like Paris green in due to their poisonous nature. In the UK, the Arsenic Act of 1851 regulated the sale and purchase of arsenic compounds, requiring vendors to record buyer details, while subsequent concerns led to industry self-regulation and reports limiting arsenic in wallpapers by the early 1900s, with a 1900 report declaring British wallpapers practically free of arsenic. As an , Paris green faced stricter controls in the mid- to late . In the , its agricultural use declined sharply by the 1940s with the introduction of less toxic alternatives, and it was no longer in commercial production by the mid-. The Environmental Protection Agency (EPA) further restricted arsenical pesticides, with most organic arsenicals like Paris green no longer registered for use by the 1980s following reviews under the Federal , Fungicide, and Rodenticide Act (FIFRA). In the , Council Directive 79/117/EEC prohibited the marketing and use of plant protection products containing specified arsenical compounds, effective from 1979 to protect human health and the environment. Regulations on Paris green as a pigment emphasized occupational and carcinogenicity. In 1978, the (OSHA) set a of 10 µg/m³ for inorganic , including compounds like copper acetoarsenite, averaged over an 8-hour workday, to prevent workplace poisoning. The International Agency for Research on Cancer (IARC) classified inorganic arsenic compounds as Group 1 carcinogens in 1980, based on sufficient evidence of and risks from occupational exposure.

Modern Reproductions and Alternatives

In , synthetic organic pigments emerged as safe alternatives to Paris green, providing vibrant green hues without the risks associated with . Phthalocyanine green (Pigment Green 7, or PG7), first synthesized in 1935, offers a transparent, intense blue-shade green that surpasses the and versatility of historical arsenic-based greens like Paris green, and it has become a standard in modern artist paints and industrial applications. Similarly, cobalt titanate green (PG50), developed in the mid-20th century, delivers a stable, non-toxic yellowish-green tone suitable for opaque formulations, with excellent resistance to light, heat, and chemicals, making it ideal for long-term use in paints and ceramics. Contemporary pigment suppliers produce non-toxic reproductions of Paris green to replicate its iconic emerald tone for artistic and decorative purposes. These versions, often based on derivatives, maintain high UV stability while avoiding opacity issues common in some synthetic greens; for instance, Pigments introduced a Paris Green Reproduction in 2018, certified non-toxic and compatible with oils, acrylics, and watercolors, though it requires careful mixing to achieve the original's depth. Such products enable artists to evoke historical without health hazards, with availability expanding in the through specialized vendors. In art conservation, museums employ targeted techniques to manage original Paris green artifacts, prioritizing identification and safe handling to mitigate arsenic exposure. The Poison Book Project at the , launched in 2019 and expanded through 2022 studies, developed protocols for detecting arsenic in bookbindings via portable , recommending isolation, labeling, and minimal manipulation for affected items, which has influenced global museum practices for arsenic-laden decorative arts. For restorations, conservators use digital color matching tools, such as spectrophotometers, to replicate faded Paris green shades with modern non-toxic pigments, ensuring visual fidelity while preserving object . The cultural legacy of Paris green extends to contemporary eco-art, where its toxicity informs discussions on environmental harm and in creative practices. Performances like "Going (Paris) Green" (2024), a collaboration between artist Julie Laffin and scholar Jennifer Natalya Fink, explore greenwashing and pigment dangers through interactive installations, highlighting the 's role in critiquing industrial . Recent studies, such as the University of Delaware's 2022 analysis of in 19th-century bookbindings, have spurred awareness campaigns on hidden toxins in antiques, influencing eco-art initiatives that advocate for safer material alternatives in heritage preservation.

References

  1. https://pubchem.ncbi.nlm.nih.gov/compound/Copper-acetoarsenite
  2. https://ehp.niehs.nih.gov/doi/10.1289/ehp.1104405
  3. https://www.webexhibits.org/pigments/indiv/history/emerald.html
  4. https://www.nps.gov/articles/why-is-white-haven-painted-green.htm
  5. https://www.udel.edu/udaily/2022/june/poison-books-arsenic-bindings-covers-pigments-dyes/
  6. https://blog.library.si.edu/blog/2018/08/20/if-books-could-kill-a-deadly-secret-in-the-cullman-library/
  7. https://pmc.ncbi.nlm.nih.gov/articles/PMC3179678/
  8. https://cameochemicals.noaa.gov/chemical/2981
  9. https://monographs.iarc.fr/ENG/Classification/index.php
  10. https://pubchem.ncbi.nlm.nih.gov/compound/22833492
  11. https://sitem.herts.ac.uk/aeru/iupac/Reports/2550.htm
  12. https://www.uvm.edu/uvmnews/news/discovery-how-colorado-potato-beetles-beat-pesticides
  13. https://colourlex.com/project/emerald-green/
  14. https://www.nature.com/articles/s40494-016-0078-1
  15. https://dspace.mit.edu/bitstream/handle/1721.1/156424/39370331-MIT.pdf?sequence=1
  16. https://www.winsornewton.com/blogs/articles/emerald-green
  17. https://www.nature.com/articles/s40494-024-01192-7
  18. https://cameo.mfa.org/wiki/Emerald_green
  19. https://www.webexhibits.org/pigments/indiv/overview/emerald.html
  20. https://www.getty.edu/publications/virtuallibrary/0892366389.pdf
  21. https://janeaustensworld.com/2010/03/05/emerald-green-or-paris-green-the-deadly-regency-paint/
  22. https://www.degruyterbrill.com/document/doi/10.1515/9781789203202-005/html?lang=en
  23. https://discovery.ucl.ac.uk/id/eprint/10047160/12/Werrett_Compound_Histories_7.pdf
  24. http://www.firegold.com/pigment.html
  25. https://www.aiche.org/sites/default/files/cep/20151248_r.pdf
  26. https://macmillan.yale.edu/sites/default/files/files/colloqpapers/08mcwilliams.pdf
  27. https://www.nature.com/articles/s40494-022-00834-y
  28. https://www.chemicalbook.com/CASEN_12002-03-8.htm
  29. https://www.researchgate.net/publication/272312947_Degradation_of_Emerald_green_in_oil_paint_and_its_contribution_to_the_rapid_change_in_colour_of_the_Descente_des_vaches_1834-1835_painted_by_Theodore_Rousseau
  30. https://pyrodata.com/sites/default/files/paris%20green.pdf
  31. https://www.skylighter.com/blogs/how-to-make-fireworks/blue-stars-part-2
  32. https://morrowarchival.com/products/paris-green-413265258
  33. https://www.color-name.com/paris-green.color
  34. https://my.meural.netgear.com/editorial/333/a-deadly-hue:-scheele%27s-green
  35. https://www.jacksonsart.com/blog/2021/10/25/pigment-colour-index-green-pigments/
  36. https://www.artiscreation.com/green.html
  37. https://www.earthpigments.com/paris-green-reproduction/
  38. https://underthemoonlight.ca/2018/03/17/a-dark-history-of-arsenic-greens/
  39. https://www.concertina.net/forums/index.php?/topic/17957-green-dye-in-victorian-concertina-bellows/
  40. https://cameo.mfa.org/wiki/Copper_arsenite
  41. https://www.researchgate.net/publication/349441126_Emerald_Green_versus_Scheele%27s_Green_Evidence_and_Occurrence
  42. https://www.nationalgeographic.com/premium/article/these-green-books-are-literally-poisonous
  43. https://bonjourparis.com/art/paris-green-paint-pigment-packed-with-poison/
  44. https://www.theartsection.com/pre-raphaelites-victorian-avant-garde
  45. https://www.tate.org.uk/research/tate-papers/34/the-making-of-a-triptych-the-annunciation-and-adoration-of-the-magi-1861-by-edward-burne-jones
  46. https://publications.artic.edu/monet/reader/paintingsanddrawings/section/135551
  47. https://ipmworld.umn.edu/ragsdale-potato-beetle
  48. https://www.labmanager.com/how-colorado-potato-beetles-beat-pesticides-24713
  49. https://www.govinfo.gov/content/pkg/GOVPUB-A-5c29a92330ee1fabe34f22c450a3a1dd/pdf/GOVPUB-A-5c29a92330ee1fabe34f22c450a3a1dd.pdf
  50. https://www.biodiversitylibrary.org/content/part/JAMCA/MN_V20_N2_P105-110.pdf
  51. https://news.prairiepublic.org/main-street/2019-11-09/potato-bugs-and-paris-green
  52. https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/paris-green
  53. https://trove.nla.gov.au/newspaper/article/83149504
  54. https://www.mcgill.ca/oss/article/history-general-science/arsenic-and-old-books
  55. https://victorianparis.wordpress.com/2023/11/01/the-arsenic-century-when-your-walls-could-kill-you/
  56. https://cool.culturalheritage.org/coolaic/sg/bpg/annual/v39/bpga39-10.pdf
  57. https://www.tandfonline.com/doi/abs/10.1080/01971360.2022.2031457
  58. https://pubsapp.acs.org/cen/whatstuff/stuff/7927sci3.html
  59. https://www.skylighter.com/blogs/how-to-make-fireworks/copper-powder-green-and-blue-stars
  60. https://www.artandobject.com/news/green-19th-century-cultural-history
  61. https://blog.americanduchess.com/2022/05/a-little-history-of-arsenic-green.html
  62. https://archive.cdc.gov/www_atsdr_cdc_gov/csem/arsenic/what_routes.html
  63. https://digitalcommons.buffalostate.edu/cgi/viewcontent.cgi?article=1020&context=museumstudies_theses
  64. https://www.wjgnet.com/2220-6132/full/v3/i2/96.htm
  65. https://pmc.ncbi.nlm.nih.gov/articles/PMC3183630/
  66. https://pmc.ncbi.nlm.nih.gov/articles/PMC4767610/
  67. https://www.ncbi.nlm.nih.gov/books/NBK541125/
  68. https://www.gov.uk/government/publications/arsenic-properties-incident-management-and-toxicology/arsenic-toxicological-overview
  69. https://cameochemicals.noaa.gov/chris/CAA.pdf
  70. https://pubmed.ncbi.nlm.nih.gov/12897217/
  71. https://www.who.int/news-room/fact-sheets/detail/arsenic
  72. https://wwwn.cdc.gov/TSP/MMG/MMGDetails.aspx?mmgid=1199&toxid=278
  73. https://hyperallergic.com/329747/death-by-wallpaper-alluring-arsenic-colors-poisoned-the-victorian-age/
  74. https://www.sciencehistory.org/stories/magazine/an-everyday-poison/
  75. https://www.theparisreview.org/blog/2018/05/02/scheeles-green-the-color-of-fake-foliage-and-death/
  76. https://www.jack-the-ripper-tour.com/generalnews/poisoned-by-flowers/
  77. https://www.chemeurope.com/en/encyclopedia/Paris_Green.html
  78. https://www.nature.com/articles/news030609-11
  79. https://thegardenhistory.blog/2023/11/04/poisoning-pests-plants-and-people/
  80. https://www.facebook.com/groups/1706748102970911/posts/3051935535118821/
  81. https://pmc.ncbi.nlm.nih.gov/articles/PMC7495674/
  82. https://jvc.oup.com/2023/12/14/arsenic-and-old-wallpapers/
  83. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1018
Add your contribution
Related Hubs
User Avatar
No comments yet.