Making colour
Toxic colours: lead white, arsenic green and radium
Some of the most useful colours ever made were poisons. They harmed the people who made them more than those who used them.
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Many historic colours were poisonous. Lead white, the main white of painters for two thousand years, damaged the nerves of those who made it. Bright greens made with arsenic coloured Victorian wallpaper, sweets and dresses. In the 1920s, luminous paint containing radium killed young women who painted watch dials. In each case the workers suffered first and worst.
Lead white
Lead white was made by hanging strips of lead over vinegar in sealed pots packed in dung or bark. After some weeks the metal was coated in a white crust, which was scraped off and ground. It makes a warm, dense, quick-drying white that painters valued greatly. It was also used as face powder from ancient Greece to eighteenth century Europe. Lead builds up in the body and harms the brain, nerves and kidneys. Titanium white replaced it in the twentieth century, and most countries now restrict or ban lead in household paint.
Arsenic greens
In 1775 the Swedish chemist Carl Wilhelm Scheele made a bright green from copper and arsenic. A stronger version, known as emerald green or Paris green, followed in 1814. They were cheap and vivid at a time when good greens were scarce, and they went into wallpaper, paint, cloth, artificial flowers and even food colouring. Workers who handled the powder developed sores and worse. In damp rooms the wallpaper could give off arsenic fumes. The idea that Napoleon was poisoned by his wallpaper on Saint Helena is unproven. Paris green ended its days as an insecticide.
Radium
Radium, discovered in 1898, was mixed with a zinc compound to make paint that glowed in the dark. From 1917 factories in the United States employed young women to paint the numbers on watch and instrument dials. They were told to bring their brushes to a point between their lips. Radium behaves like calcium in the body and settles in bone. Many of the women developed severe jaw decay, anaemia and bone cancer. Their court cases in the 1920s and 1930s helped to establish safety rules for workers and the right to sue an employer.
Colours on this page
Sources and further reading
- Scheele's green on Wikipedia
- ColourLex: Lead white
- ColourLex: Emerald green
- Harvard T.H. Chan School of Public Health: Deadly occupation, forged report
- World Health Organization: Lead poisoning
Original text by the Rang desk, written with AI assistance and checked against the sources above. Meanings of colour vary from place to place and person to person. If we have something wrong, tell us.