Ethyl mercaptan (ethanethiol) — properties & hazards overview
Boiling point
≈ 35 °C
Flash point
~ −45 °C (very low)
Odour threshold
Extremely low (ppb)
Water solubility
Low; increases as salts
Flammability
Very low FP; vapours ignite
Toxicity
Irritant; headaches/nausea
Chronic risk
Sensitisation/odour
Environmental
Odour / COD
| Property | Value / Note |
|---|---|
| Chemical identity | Ethanethiol, “ethyl mercaptan”; CH₃–CH₂–SH, intensely skunky/garlic odour. |
| Molar mass | ≈ 62.13 g/mol |
| Physical state | Clear, very odorous liquid; vapours heavier than air; forms flammable mixtures with air. |
| Reactivity | Reduced sulfur (R–SH); oxidises to disulfides/sulfonates; incompatible with strong oxidisers; forms mercaptide salts with bases/metals. |
| Behaviour in gas streams | Low intrinsic solubility → efficient removal with alkaline liquor plus controlled oxidant; demister performance is critical to prevent odour slip. |
| Best analytical detection | GC–PFPD (sulfur-selective) — highly sensitive/selective for thiols; quantifies speciated ethanethiol down to ppb for compliance and troubleshooting. |
*Indicative values; verify exact limits and physical data via current SDS (“verify via SDS”).