text: Uses Naphthalene is used mainly as a precursor to derivative chemicals. The single largest use of naphthalene is the industrial production of phthalic anhydride, although more phthalic anhydride is made from o-xylene.
  Fumigant
  Naphthalene has been used as a fumigant. It was once the primary ingredient in mothballs, although its use has largely been replaced in favor of alternatives such as 1,4-dichlorobenzene. In a sealed container containing naphthalene pellets, naphthalene vapors build up to levels toxic to both the adult and larval forms of many moths that attack textiles. Other fumigant uses of naphthalene include use in soil as a fumigant pesticide, in attic spaces to repel insects and animals such as opossums, and in museum storage-drawers and cupboards to protect the contents from attack by insect pests.
  Solvent
  Molten naphthalene provides an excellent solubilizing medium for poorly soluble aromatic compounds. In many cases it is more efficient than other high-boiling solvents, such as dichlorobenzene, benzonitrile, nitrobenzene and durene. The reaction of C60 with anthracene is conveniently conducted in refluxing naphthalene to give the 1:1 Diels–Alder adduct. The aromatization of hydroporphyrins has been achieved using a solution of DDQ in naphthalene.
  Derivative uses
  The single largest use of naphthalene is the production of phthalic anhydride, which is an intermediate used to make plasticizers for polyvinyl chloride, and to make alkyd resin polymers used in paints and varnishes.