Naphthalene can be produced from coal or from petroleum. Production volume in the United States decreased significantly from a peak of 409.000 tons in 1968 to 101.000 tons in 1994. Production capacity has remained relatively stable in recent years, with estimated capacity for 2004 at 97,700 tons. The major commercial use of naphthalene is in the manufacture of polyvinyl chloride (PVC) plastics. The major consumer products made from naphthalene are moth repellents, in the form of mothballs or crystals, and toilet deodorant blocks. It is also used for making dyes, resins, leather tanning agents, and the insecticide carbaryl. It enters the environment from industrial uses, from its use as a moth repellent, from the burning of wood or tobacco and from accidental spills.
Most of the naphthalene entering the environment is discharged to the air. The largest releases result from the combustion of wood and fossil fuels and the off-gassing of naphthalene-containing moth repellents. Smaller amounts of naphthalene are introduced to water as the result of discharges from coaltar production and distillation processes. The coal-tar industry is also a major source of the small amounts of naphthalene that are directly discharged to land.
In the atmosphere naphthalene is broken down rapidly, usually within one day. From the atmosphere it can also very slowly be depositioned in water. It has a rather low water solubility of 31,7 µg/l and a rather low tendency to adsorb to particles. It is expected that only 10% of the naphthalene in water bodies is associated with particles. The main loss of naphthalene from water water bodies is due to evaporate into the atmosphere.
rather low water solubility of .
Naphthalene evaporates easily. That is why you can smell mothballs. In the air, moisture and sunlight make it break down, often within 1 day. Naphthalene can change to 1-naphthol or 2-naphthol. These chemicals have some of the toxic properties of naphthalene. Some naphthalene will dissolve in water in rivers, lakes, or wells. Naphthalene in water is destroyed by bacteria or evaporates into the air. Most naphthalene will be gone from water in rivers or lakes within 2 weeks.
Naphthalene binds weakly to soils and sediments. It easily passes through sandy soils to reach underground water. In soil, some microorganisms break down naphthalene. When near the surface of the soil, naphthalene will evaporate into air. Microorganisms present in the soil will break down most of the naphthalene in 1–3 months. Naphthalene does not accumulate in the flesh of animals and fish that you might eat. If dairy cows are exposed to naphthalene, some naphthalene will be in their milk; if laying hens are exposed, some naphthalene will be in their eggs. Naphthalene and the methylnaphthalenes havebeen found in very small amounts in some samples of fish and shellfish from polluted waters.