Naphthalene balls, also known as moth balls or camphor balls, are spherical pieces of a white solid material containing at least 98 percent naphthalene. They were widely used to repel moths and cockroaches and as deodorants for urinals and bathrooms. Naphthalene is carcinogenic and poses several other health hazards, so it is no longer used for household purposes in several countries. It is still widely available in several Asian countries, where naphthalene balls are used to preserve woolen fabrics.

Naphthalene balls are useful for keeping moths off woolen garments


Naphthalene is an organic chemical that occurs as a white powder or solid. It has a strong, distinctive odor. Its chemical formula is C10H8, which is represented by two fused benzene rings. It has a melting point of 77 degrees Celsius and is flammable with a flashpoint of 88 degrees Celsius. Naphthalene is heat-sensitive and slowly sublimes, or transforms directly from the solid to gaseous state without becoming a liquid, at room temperature. Moth balls and urinal cakes are made by compressing flakes of solid naphthalene in a die press.

Health Effects

Although naphthalene balls are widely used by consumers for their distinctive mothball odor, naphthalene is a potentially harmful chemical and is dangerous to inhale. It readily sublimates at room temperature, transforming directly to a gaseous state. Inhalation of the gas irritates the respiratory tract and can destroy red blood cells, even after relatively short periods of exposure. Inhalation of naphthalene also has been linked to cataracts, optic nerve inflammation, nausea, vomiting, profuse perspiration and kidney and liver damage. Ingestion of the balls can be fatal. Naphthalene is also an eye and skin irritant.

Safety Precautions

Naphthalene balls should be stored in closed containers, well out of the reach of toddlers and children. They need to be kept away from open flames, moisture and oxidizing agents in a cool, dry, well-ventilated area. Do not inhale the fumes from the balls. Avoid contact with skin and eyes and wash your hands thoroughly with soap and water after handling them.


Naphthalene is widely used to deal with cockroach and moth infestations and for its fragrance. It is often packaged with stored woolen clothing during the summer months and used as an air freshener in closets and urinal cakes. It has industrial applications as a surface acting agent, in tanning, in dyes and in other organic chemical applications.