Long-term Health Effects of Exposure to Naphthalene Background and status of Naphthalene as a Toxic Air Contaminant and Potential Carcinogen

Naphthalene (CAS Registry Number: 91-20-3) is a natural constituent of coal tar, comprising approximately 11% of that material by weight (HSDB, 2003). It is present in gasoline and diesel fuels. All pesticide registrations of naphthalene, including use as a moth repellent, were cancelled in California in 1991 due to data gap inadequacies. However, naphthalene is included on a list of "inert" or "other ingredients" found in registered pesticide products (U.S. EPA, 2004). It is used in the manufacture of a wide variety of industrial products. A profile dated 1987 showed proportionate naphthalene use for various products as: Phthalic anhydride, 60%; 1-naphthyl methyl carbamate insecticide and related products (tetralin and 1-naphthol), 10%; dispersant chemicals, 10%; moth repellent, 6%; synthetic tanning agents, 5%; miscellaneous uses, 5%; exports, 4% (HSDB, 2003). Other products listed as derived from naphthalene include phthalic and anthranilic acids, naphthols, naphthylamines, naphthalene sulfonates, synthetic resins, celluloid, lampblack, smokeless powder, anthraquinone, indigo, perylene, and hydronaphthalenes (NTP, 1992; HSDB, 2003).