Methylamine (monomethylamine, MMA) — properties & hazards overview
Boiling point
−6.3 °C
Flash point
−10 °C
Explosion limits (air)
4.9 – 20.7 vol%
Water solubility
≈ 1 080 g/L — very soluble
Toxicity
Corrosive to airways
Flammability
FP −10 °C; 4.9–20.7%
Chronic risk
Respiratory irritation
Environmental
Odour; nitrogen load
| Property | Value / Note |
|---|---|
| Chemical formula | CH₃NH₂ |
| Molar mass | 31.06 g/mol |
| Physical state | Gas at ambient; supplied as 40% aqueous solution or liquefied gas |
| Basicity | pKa (conjugate acid) ≈ 10.6 — a stronger base than ammonia, so it is captured completely at pH 3–4. |
| Odour | Fishy, ammoniacal; threshold in the low ppb range. |
| Typical sources | Offal and fish processing, rendering, protein degradation, pharmaceutical and agrochemical synthesis. |
| Best analytical detection | FTIR for continuous multi-component stack measurement; PID/FID for trending; ion chromatography of the scrubber liquor to confirm the captured load as methylammonium. |
*Values are indicative and may vary by source. For safety and design, always consult current SDS and regulations.