Naphthalene is a crystalline, white hydrocarbon, with a strong smell. It is best known as the main ingredient in mothballs, urinal deodorizer blocks, and can be used as an antiseptic. In mothballs, it is used as an insecticide or pesticide.
Naphthalene is toxic. In humans, being exposed to naphthalene can destroy red blood cells. Naphthalene may also cause cancer.