Paris green (copper(II) acetoarsenite)

Chemical characteristics

The substance combines copper in the +2 oxidation state with acetate and arsenite anions. Its composition includes a copper-containing fraction (copper ion), an acetate fraction (acetate group) and arsenite moieties (arsenite ion); these parts together form the characteristic green solid commonly called Paris green. As a pigment it produces a vivid, bluish-green color and behaves as a relatively stable, insoluble solid in dry paint films, though it can degrade under some environmental conditions (compound components).

History and uses

Developed and popularized in the 19th century, its rich color made it fashionable in interior decoration and art. It was later applied as an agricultural insecticide, notably against leaf-eating pests. Over time, manufacturers and artists adopted other green pigments for safety and permanence.

Hazards and legacy

Because Paris green contains arsenic it is highly toxic; exposure can cause acute poisoning and long-term health risks. Reports of poisoning linked to wallpapers and misuse as an insecticide prompted reduced use and regulatory restrictions. Today it is mainly of historical and conservation interest rather than practical use, and modern alternatives have largely replaced it (oxidation state reference).

Notable distinctions

• Often confused with other arsenical greens, but chemically distinct as copper(II) acetoarsenite.
• Valued historically for its color, abandoned for public-health reasons.