Like other common colors, green has several completely opposite associations. While it is the color most associated by Europeans and Americans with good health, it is also the color most often associated with toxicity and poison. There was a solid foundation for this association; in the nineteenth century several popular paints and pigments, notably verdigris, vert de Schweinfurt and vert de Paris, were highly toxic, containing copper or arsenic.[d] The intoxicating drink absinthe was known as "the green fairy".
Why were popular paints and pigments in the nineteenth century highly toxic?
copper or arsenic