Arsenic is a silvery-white, brittle poisonous chemical element, compounds of which are used to make insecticide, glass, medicines, semiconductors and more. At the Franklin Glass plant on Butler's South Side, it was used to remove air bubbles from molten glass.

Arsenic and its compounds are toxic to animals. In low doses, arsenic produces nausea, vomiting, and diarrhea. In larger doses, it causes abnormal heart beat, damage to blood vessels, and a feeling of "pins and needles" in hands and feet. Small corns or warts may begin to develop on the palms of the hands and the soles of the feet. Direct contact with the skin can cause redness and swelling, according to the Centers for Disease Control.

Long term exposure to arsenic can cause cancer. Inhalation can result in lung cancer. If swallowed, cancer is likely to develop in the bladder, kidneys, liver, and lungs. In large doses, arsenic and its compounds can cause death by compromising the body's red blood cells' ability to carry oxygen.