Carbon Monoxide — properties & hazards overview
Boiling point
−191.5 °C
Explosion limits (air)
12.5 – 74 vol%
Autoignition
≈ 605 °C
Water solubility
0.028 g/L (20 °C) — negligible
Toxicity
COHb; no odour warning
Flammability
12.5–74 vol%
Chronic risk
Hypoxic organ damage
Environmental
Ozone precursor
| Property | Value / Note |
|---|---|
| Chemical formula | CO |
| Molar mass | 28.01 g/mol |
| Physical state | Colourless, odourless gas; density almost equal to air |
| Reactivity | Chemically inert towards water and alkali — it does not absorb. Oxidises to CO₂ over a catalyst or at high temperature. |
| Occupational limits | Order of 20–30 ppm TWA / 100 ppm STEL — verify against local regulation. |
| Typical sources | Incomplete combustion, pyrolysis and gasification (syngas), reduction furnaces, flares running rich. |
| Best analytical detection | NDIR for continuous stack measurement (the reference method), electrochemical cells for portable and safety detection, FTIR where CO is one of several species. CO is also the standard indicator for combustion quality. |
*Values are indicative and may vary by source. For safety and design, always consult current SDS and regulations.