When Color Kills: Toxic Pigments Through the Ages
- Liz Publika
- Jul 15, 2019
- 5 min read
Updated: Dec 21, 2025
Napoleon Bonaparte: revolutionary military commander, first Emperor of France, and champion of widely influential civil codes.
Vincent Van Gogh: Dutch oil painter of starry nights and sunflowers, post-Impressionist idol, self-mutilating psychiatric patient.
What did these two men — born in different centuries — have in common?
According to historians, they were both likely poisoned by pigments.
After being exiled to a remote island in the Atlantic Ocean, Napoleon’s health quickly faded, and ultimately he succumbed to stomach cancer. But the cause of death is not so simple. Many believe that his cancer could be attributed, at least in part, to his wallpaper. The ornate floral patterns adorning the walls of Longwood House were painted with a pigment known as Scheele’s green. This pigment is now obsolete. The reason? When exposed to prolonged humidity — as was certainly the case in a washroom on a tropical island, where Napoleon reportedly soaked in long, luxurious baths — a type of mold can develop. This process results in the release of arsenic gas, which we now know is extremely carcinogenic.
Indeed, in the 20th-century, long after his death, toxicology tests were conducted on Napoleon’s hair. As you might have guessed by now, high levels of arsenic were found in his follicles.
For his part, Van Gogh has long been revered as a brilliant, yet mad artistic genius; that madness, however, may have had something to do with the lead in his paint. His “impasto technique, based on thick layers of paint,” meant that he used “colors with a high content of lead, such as white lead (lead carbonate) or chrome yellow (lead chromate), in the mixtures he prepared.” He also apparently had a tendency to lick his brushes, which could have led to the ingestion of these paints. Lead poisoning can lead to a whole host of symptoms, which were, incidentally, similar to those exhibited by Van Gogh—including anemia, abdominal pain, and seizures.
Though they have different effects and are derived from different sources, arsenic and lead are similar in that they’re both heavy metals. Actually, many pigments from throughout the ages have contained various types of heavy metals in different amounts, and with differing levels of toxicity.
First, it is worth noting that the term heavy metals is difficult to define precisely, as it refers to an ill-defined subset of elements that share metallic properties. Not all heavy metals are harmful; some, such as iron and zinc, are essential for human survival. The problem lies in their tendency to bioaccumulate, meaning their concentration increases within a biological organism over time. Had Napoleon encountered the green wallpaper only briefly, or had Van Gogh used lead paint only occasionally, the effects might not have been as severe.
Besides these two examples, other historical pigments had plenty of their own heavy metal problems. Orpiment, or King’s yellow, can be found on ancient Egyptian papyrus scrolls. The chemical name for this pigment is arsenic sulfide. As you might imagine, this means the fumes were both poisonous and — owing to the sulfuric component — very stinky.
Yellow pigments in general seem to have been notoriously riddled with safety hazards. For instance, Frank Cyr (1900-1995), an American educator, unveiled a plan to make all school buses uniform and easy to see, rain or shine — hence the bright yellow we associate with school buses. However, the first pigment used on these buses, which “came to be known as ‘National School Bus Chrome,’” contained a particularly noxious type of chromium. Hexavalent chromium is highly reactive, aggressively seeking electrons and damaging DNA in the process.
Likewise, uranium — one of the heaviest metals — gives “uranium yellow” its hue. It also gave users of the pigment radiation poisoning. Until the second half of the 20th-century, it was used “to tint glass and ceramics in shades ranging from yellow-green to orange and red,” but it dates all the way back to 79 AD Italy. During the war efforts of World War I and World War II, the pigment was used for detailed painting on military vehicles. Young women assigned to the task often shaped their brushes by rolling them between their lips to create a fine point, unknowingly exposing themselves to dangerous levels of radiation.
Historically, the track record of red pigments has been scarcely better. Vermilion was used for millennia, from ancient China to Renaissance Europe. It was produced through the mining of cinnabar, an ore that contains mercury and proved so toxic that it often cost miners their lives. Eventually, vermilion was replaced by cadmium red, though this substitute has also faced increasing criticism in recent decades. While cadmium remains permitted in paints, the European Union has banned its use in certain products, and the EPA’s Office of Resource Conservation and Recovery has placed it on a list of chemicals targeted for elimination, reduction, or substitution because of their toxicity and tendency to accumulate in the body.
These efforts make sense, as cadmium exposure is linked to renal dysfunction, lung disease, lung cancer, and bone defects. In 2010, Miley Cyrus’ jewelry line was pulled from WalMart because of unsafe levels of the heavy metal. That same year, Claire’s recalled 19,000 friendship bracelets for the same reason. But many companies, like Winsor & Newton, still market paints made with cadmium red pigments, claiming the levels aren’t high enough to exert a toxic effect.
Though most of the worst heavy metal offenders have been phased out of the world of pigments, if you peruse the aisles of an arts and crafts store, you will find that some products contain warning labels. This is due to the Labeling of Hazardous Art Materials Act of 1988, which requires arts and crafts materials manufacturers to identify ingredients known to pose chronic health hazards on product labels with appropriate warnings. The law also mandates the provision of safety data sheets that detail potential health risks, first aid measures, flammability, and other relevant safety information.
But even if you still see paints labeled “Cadmium Red” or “Lead White,” these are often actually hues rather than the historic, true pigment. In this context, a hue refers to “a color that is made up of different pigments than the original,” precisely because of the pigment’s toxicity, or because of its unavailability.
Still, it’s hard to say if this new generation of hue alternatives is decidedly safer than the heavy metal pigments of yesteryear. Monona Rossol, who runs a nonprofit devoted to arts safety, said of naphthol red in place of cadmium:
“We know what happens in two weeks after animals ingest it, but we don’t know much else. There is not enough cancer information to classify it and the other chronic hazards are only based on guesses since there is no hard data. In other words, you want artists to trust this pigment as a safe replacement without telling them that it could one day turn out to be a really bad actor if someone actually tests it for chronic hazards.”
To be sure, our understanding of biochemistry has come a long way since Napoleon languished on a volcanic island, as has our healthcare system. But there is something to be said for hindsight — it is, as they say, always 20/20. In the 18th-century, who knew that color could kill? Might we look back a decade, a century, or a millennia from now, and rue what we didn’t know about the pigments in use today? Sure, green paint no longer contains arsenic… but maybe there’s another unknown toxin lurking, accumulating in its depths.
Note* All images are sourced from the public domain.