Formaldehyde — properties & hazards overview
Boiling point (gas)
~ −19 °C
LEL–UEL (gas)
~ 7–73 vol%
Water solubility
Very high (forms formalin)
Odour threshold
~ 0.05–1 ppm (not a safe indicator)
Toxicity
high (irritant)
Flammability
gas flammable; solution varies
Chronic risk
carcinogenic + sensitiser
Environmental
VOC / odour
| Property | Value / Note |
|---|---|
| Physical state (20 °C) | Gas; commonly handled as aqueous solution (formalin ~37% w/w with methanol stabilizer). |
| Reactivity | Polymerises; forms paraformaldehyde on standing; readily oxidised to formic acid/formate. |
| Uses | Resins (UF/MF/PF), disinfectants, preservatives, chemical intermediate. |
*Gas properties differ from formalin; use process-specific data for design.