Mad about Science: Deadly Paint

By Brenden Bobby
Reader Columnist

You may know a little about my favorite hobby: miniature painting. It’s not an incredibly dangerous hobby, but it comes with its own set of risks. 3-D printing the miniatures with photopolymer resin exposes the unprepared user to airborne carcinogens with the potential for yet-uncertain long-term effects to health. Superglue can break down into cyanide gas when exposed to heat. Using an airbrush spreads a fine mist of acrylic in the air, which can end up in the lungs or eyes if not using proper protective equipment.

Painting has traditionally been a surprisingly dangerous hobby, despite the seemingly relative safety of standing in one place painting. Recreating accurate colors on canvas requires specialized chemical pigments that can pose a risk to humans. One of these is cadmium.

The element cadmium is used in a huge variety of applications. Artists have frequently used cadmium in yellow pigment. Being a lighter color, yellow is notorious among artists for turning out rather transparent when applied with a medium. In order to achieve maximum vibrancy, an artist must apply many layers of yellow over a surface or base coat in white and paint yellow over it. 

Queen Elizabeth I and her famous porcelain hue. Courtesy photo.

Yellow is a color that doesn’t traditionally exist in a vacuum — it’s often a representation of sunlight flickering off the surface of other materials, such as waves or glass at sunset. Pure white looks very strange when applied in these scenarios, and oil paints will blend together when applied at similar times, which dilutes the white and makes the yellow harder to apply. Cadmium solves that problem, but it comes with a cost.

Cadmium sulfide is safe to use when suspended in a medium, which is a binding agent that allows for pigment to be spread across a surface. The dry powder pigment presents a risk of inhalation, which can cause myriad issues ranging from increased risk of bone fractures and cancers. 

A greater risk comes from cadmium yellow paint being washed down a drain and later absorbed by plants intended for consumption. Ingestion of cadmium causes liver and kidney damage, weakens the skeletal system and presents the risk of a whole host of cancers. It’s easy enough to say: “Just don’t wash the paint down the drain,” but the brush must be cleaned between uses. With acrylic paint, this is done with water in a cup or a jar, while oils require a powerful solvent like turpentine or mineral spirits. It’s possible to set paint water in a clear container in the windowsill to let it evaporate over time, but you’ll still have cadmium in that container. 

Green is another color with a lethal history. It has sickened and slain paupers and emperors alike, and has been used to create beauty and floral facsimile while harboring a dangerous secret.

Scheele’s green was a popular pigment in Victorian England — particularly useful for creating copies of flowers and plants out of dyed silk that the upper crust purchased at great expense to bring class and natural beauty to their homes. As has been the case for much of human history, value was extracted from misery, as poor flower-makers toiled away for England’s elite while literally decomposing in the process. 

The workers’ fingernails cracked and turned yellow while lesions crept up their arms as they crafted the floral facsimiles, because the pigment used in Scheele’s green was laced with arsenic. It was created by heating sodium carbonate (soda ash) with arsenious oxide and copper sulfate. This made it beautiful, but also made it very easy to inhale and become stuck to every surface of the workers’ skin.

Scheele’s green was a color all its own and it mimicked nature very well, and was also used in wallpaper, which was even found in Napoleon’s home in exile on St. Helena. This was his favorite color, and it’s believed that his exposure to moldy wallpaper may have played a major role in his death. Napoleon died of stomach cancer, likely caused or exacerbated by arsenic exposure, which was confirmed when scientists tested a lock of his hair.

The most infamous of all lethal paints may have played a part in the slow demise of another historic European monarch. It’s a paint that’s produced to this day and carries with it a dark stigma, a direct inversion of the brilliance of its hue: lead white.

White lead is an extremely vibrant and durable paint. Similar to yellow, white pigment often struggles to cover surfaces with uniform opacity. This causes lower layers to peek through, creating unfortunate shadows on ridges or caking multiple layers of white to ruin the texture of the piece. This was solved by lead carbonate. It’s so good at vibrant coverage that it was applied for many uses well beyond painting.

Queen Elizabeth I was famously depicted with an almost porcelain hue to her skin. This look was achieved by her use of a makeup called Venetian ceruse, which was produced using a lead carbonate pigment. She was putting lead in powder form all over her skin, which certainly must have been absorbed through her pores throughout her life.

White paint is still in use to this day, though its production and sale is strictly controlled. The world didn’t understand the toxicity of white lead until 31 years after Queen Elizabeth’s death.

Stay curious, 7B.