Summary. Mothballs are small balls of chemical pesticide. Older mothballs consisted primarily of naphthalene, but due to naphthalene’s flammability, modern mothballs use 1,4-dichlorobenzene (paradichlorobenzene) instead. These ingredients have a strong, pungent odor often associated strongly with mothballs. Camphor, a carcinogenic insect repellent, can be used in mothballs also. The idea with these chemicals is to kill moths and moth larvae with the fumes. Both naphthalene and paradichlorobenzene sublimate, meaning they transition from a solid straight to a gas. The gas is toxic. More information about these chemicals can be found below.
Naphthalene. Exposure to large amounts of naphthalene may damage or destroy red blood cells. Humans, particularly children, have developed this condition, known as hemolytic anemia, after ingesting mothballs or deodorant blocks containing naphthalene. Symptoms include fatigue, lack of appetite, restlessness, and pale skin. Exposure to large amounts of naphthalene may cause nausea, vomiting, diarrhea, blood in the urine, and jaundice (yellow coloration of the skin).
1,4-dichlorobenzene. Animals given very high levels in water developed liver and kidney tumors. The United States Environmental Protection Agency (EPA) has set a maximum contaminant level of 75 micrograms of p-DCB per liter of drinking water (75 μg/L). p-DCB is also an EPA-registered pesticide. The US Occupational Safety and Health Administration (OSHA) has set a maximum level of 75 parts of p-DCB per million parts air in the workplace (75 ppm) for an 8-hour day, 40-hour workweek.
Camphor. The substance Camphor should not be confused with the Camphor Laurel, East African Camphorwood, or similar trees. Camphor is a substance found to be present in these and other trees. Although it is naturally derived, according to the MSDS sheet, Camphor is potentially harmful in the same way that Opium comes from the poppy (Papaver somniferum) or the potentially beneficial Coca leaves can be processed into a harmful substance such as Cocaine. In larger quantities, Camphor is poisonous when ingested and can cause seizures, confusion, irritability, and neuromuscular hyperactivity. In 1980, the United States Food and Drug Administration set a limit of 11% allowable camphor in consumer products and totally banned products labeled as camphorated oil, camphor oil, camphor liniment, and camphorated liniment (but “white camphor essential oil” contains no significant amount of camphor). Since alternative treatments exist, medicinal use of camphor is discouraged by the FDA, except for skin-related uses, such as medicated powders, which contain only small amounts of camphor. Modern uses of Camphor include as a plasticizer for Nitrocellulose, as a moth repellent, as an antimicrobial substance, in embalming, and in fireworks. Solid camphor releases fumes that form a rust-preventative coating and is therefore stored in tool chests to protect tools against rust.
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