Naphthalene: properties, uses, and health considerations

Physical and chemical characteristics

Naphthalene is aromatic and relatively reactive toward oxidation and electrophilic substitution compared with saturated hydrocarbons. It sublimes readily, releasing vapour that accounts for its distinctive smell. Industrially it can be converted to other chemicals by controlled oxidation and is used as a feedstock in organic synthesis. It is only sparingly soluble in water but mixes with many organic solvents.

History and production

Historically naphthalene was first isolated from coal tar during the 19th century and later obtained from petroleum fractions as refining techniques developed. Large-scale production today relies on petrochemical processes and steam recovery from coal-tar derivatives in regions where coal processing remains common.

Uses and applications

Major uses of naphthalene include its traditional role as an insect repellent in mothballs and deodorizer blocks, and as an intermediate in the manufacture of dyes, resins and other organic compounds. In laboratories and industry it serves as a building block for synthesis and as a component in certain chemical formulations.

Health, environment and safety

Naphthalene is toxic when inhaled, ingested or absorbed. It can damage red blood cells and cause hemolytic anemia, especially in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Acute exposures may produce headache, nausea and respiratory irritation. Several health agencies have evaluated its carcinogenic potential and it is regarded with caution by regulators. In the environment it can volatilize to air, where it is dispersed, and may persist in soils and sediments under some conditions.

Safe handling includes good ventilation, minimizing dust and vapour, use of protective gloves and avoiding home use of products that generate indoor vapour. Many jurisdictions have issued guidance or restrictions on consumer products containing naphthalene and encourage safer alternatives.

Further resources

• General chemical overview
• Physical and safety data
• Use in pest control
• Deodorizer and household uses
• Antiseptic and historical uses
• Insecticide and pesticide information
• Regulatory summaries
• Toxicology and hemolytic effects
• Carcinogenicity evaluations