Paris green

Paris green

Names
Other names C.I. pigment green 21, emerald green, Schweinfurt green, imperial green, Vienna green, Mitis green, Veronese green[1]
Identifiers
CAS Number	12002-03-8 Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	17215797
ECHA InfoCard	100.125.242
EC Number	601-658-7
PubChem CID	22833492
UNII	X4916E1P1M Y
UN number	1585
CompTox Dashboard (EPA)	DTXSID0024846
InChI 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
SMILES 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
Chemical formula	Cu(C2H3O2)2·3Cu(AsO2)2
Molar mass	1013.79444 g/mol
Appearance	Emerald green crystalline powder
Density	>1.1 g/cm3 (20 °C)
Melting point	> 345 °C (653 °F; 618 K)
Boiling point	decomposes
Solubility in water	insoluble
Solubility	soluble but unstable in acids insoluble in alcohol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H410
Precautionary statements	P260, P264, P273, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P362, P391, P405, P501
Lethal dose or concentration (LD, LC):
LD50 (median dose)	22 mg/kg
NIOSH (US health exposure limits):
PEL (Permissible)	[1910.1018] TWA 0.010 mg/m3[2]
REL (Recommended)	Ca C 0.002 mg/m3 [15-minute][2]
IDLH (Immediate danger)	Ca [5 mg/m3 (as As)][2]
Safety data sheet (SDS)	CAMEO MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Paris green
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°)
Source	Maerz and Paul[3]
ISCC–NBS descriptor	Vivid yellowish green
B: Normalized to [0–255] (byte)

Paris green (copper(II) acetate triarsenite or copper(II) acetoarsenite) is an arsenic-based organic pigment. As a green pigment it is also known as Mitis green, Schweinfurt green, Sattler green, emerald, Vienna green, Emperor green or Mountain green. It is a highly toxic emerald-green crystalline powder^[4] that has been used as a rodenticide and insecticide,^[5] and also as a pigment.

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.

Paris green may be prepared by combining copper(II) acetate and arsenic trioxide.^[6] The structure was confirmed by X-ray crystallography.^[7]

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.^[i] In 1822, the recipe for emerald green was published by Justus von Liebig and André Braconnot.^[8]

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.^[9][10] 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]}

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.^[11]: 220 Paris green became popular in the 19th century because of its brilliant color.^[11]: 223 It was also called emerald green because of its resemblance to the gemstone's deep color.

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.^[11]: 227 This discrepancy could be due to the fact that each experiment used a different brand of Paris green.^[11]: 228

Paris green in Descente des Vaches by Théodore Rousseau has changed significantly.^[12]

Similar natural compounds are the minerals chalcophyllite Cu
₁₈Al
₂(AsO
₄)
₃(SO
₄)
₃(OH)
₂₇·36H
₂O, conichalcite CaCu(AsO
₄)(OH), cornubite Cu
₅(AsO
₄)
₂(OH)
₄·H
₂O, cornwallite Cu
₅(AsO
₄)
₂(OH)
₄·H
₂O, and liroconite Cu
₂Al(AsO
₄)(OH)
₄·4H
₂O. 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. Paris green was used in wallpaper to some extent and may have degraded similarly.^[13] 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]}

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.^{[11]: 256 [14]}

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.^[16] It was also used widely in the Americas to control the tobacco budworm, Heliothis virescens.^[17] To kill codling moth, it was mixed with lime and sprayed on fruit trees.^[18]

Paris green was heavily sprayed by airplane in Italy, Sardinia, and Corsica during 1944 and in Italy in 1945 to control malaria.^[19] It was once used to kill rats in Parisian sewers, which is how it acquired its common name.^[20]

However, the manufacturing of the insecticide caused many health complications for factory workers, and in certain cases was lethal.^[21]

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.^{[22][23][24][25][26][27]} The Poison Book Project has cataloged books with these bindings.

Paris green became a popular paint in mass-produced wallpaper, which is believed to have shortened lifespans.^[28] Wallpaper swatches from this era have been preserved in the book Shadows from the Walls of Death.

• List of colors
• List of inorganic pigments

• Fiedler, I. and Bayard, M. A., "Emerald Green and Scheele’s Green", in Artists' Pigments: A Handbook of Their History and Characteristics, Vol. 3: E.W. Fitzhugh (Ed.) Oxford University Press 1997, pp. 219–271
• Hughes, Michael F.; et al. (2011). "Arsenic Exposure and Toxicology: A Historical Perspective". Toxicological Sciences. 123 (2): 305–332. doi:10.1093/toxsci/kfr184. PMC 3179678. PMID 21750349.
• Sorensen, W. Conner (1995). Brethren of the Net, American Entomology, 1840–1880. University of Alabama Press. pp. 124–125.
• Spear, Robert J., The Great Gypsy Moth War, A History of the First Campaign in Massachusetts to Eradicate the Gypsy Moth, 1890–1901. University of Massachusetts Press, Amherst and Boston, 2005. ISBN 1-55849-479-0

• Case Studies in Environmental Medicine - Arsenic Toxicity
• How Emerald green is made
• National Pollutant Inventory – Copper and compounds fact sheet
• Emerald green, Colourlex