When we think of the color green, words like “nature”, “life” or “fertility” often cross our minds. Yet in the past, it once carried a deadly secret. Not only is green associated with the poison of the mind – jealousy, this peculiar color is also poison in the literal sense.
The story began in the late 18th century, when Swedish chemist Carl Wilhelm Scheele invented a striking green hue made with the toxic chemical, arsenite. Called Scheele’s Green, it stood out among another thousands of duller shades with its exceptional vibrancy. Decades later, an even brighter pigment, Paris Green, was introduced as an improvement to Scheele’s Green, further deepening the world’s interest in these brilliant, but dangerous colors.
OUR OTHER BIOCHEM POSTS
Little did they know, this special glow was not only a blessing but also a curse. In other words, the very property that made these pigments so vivid – their chemical composition – is also what made them extremely toxic. As a result, they were widely used in products ranging from paint, textile dyes, wallpaper to soaps, toys and candies were produced with these pigments as essential parts of their contents.
The toxicity lies in their composition – cupric hydrogen arsenic compounds. These chemicals can disrupt cell communication and function, with frequent contact linked to cancer and heart diseases. Symptoms of poisoning were the most evident among 18th-century fabric workers and noble women wearing green dresses – all of whom were unknowingly exposed to arsenic. There is even a speculation that Napoleon’s death might have been caused by arsenic poisoning due to the heavily-dyed green wallpaper in his bedroom.
By the 20th century – fortunately – awareness of these pigments’ toxicity had increased. This resulted in these pigments being repurposed as insecticides. To this day, these greens are still considered the most dangerous pigments ever used on such a wide scale.
Credits: TED-Ed
Editor: Ngoc Anh Bui
Illustrator: Phuong Trinh Nhu