Naphthalene — properties & hazards overview
Melting point
≈ 80 °C
Boiling point
≈ 218 °C
Vapour pressure (25 °C)
≈ 0.04 hPa
Water solubility
Low (~30 mg/L)
Flammability
Combustible vapour
Toxicity
Irritant / hemolytic
Chronic risk
Suspected carcinogen
Environmental
Persistent / toxic to aquatic life
| Property | Value / Note |
|---|---|
| Appearance | White crystalline solid with characteristic odor (mothballs); sublimates readily to vapour at room temperature. |
| Odour threshold | ≈ 0.08 ppm (distinct sweet-tar smell) |
| Typical sources | Coal tar distillation, combustion of fossil fuels, tobacco smoke, creosote processes, and coking gas emissions. |
| Behaviour in gas streams | Condenses on particles or cold surfaces; forms sticky deposits in ducts and demisters. |
| Best analytical detection | FTIR spectroscopy — provides clear aromatic C–H and C=C absorption bands; ideal for direct gas-phase or filter analysis without complex sample prep. |
*Complementary confirmation by GC-MS is common, but FTIR enables rapid real-time detection of aromatic hydrocarbons in exhaust streams.