UN 2402 — Propanethiols
Placard: Flammable. ERG Guide 130. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2402 is Propanethiols, a flammable sulfur-containing liquid assigned to ERG Guide 130. Strong odor does not replace SCBA or air monitoring.
Hazard overview: FLAMMABLE sulfur-containing liquid; vapors may ignite and form explosive mixtures with air. Strong odor may be noticed at low levels, but odor is not a safe exposure-control method. Vapors are heavier than air and may travel to ignition sources and flash back.
Response guidance: For UN 2402, isolate the area, eliminate ignition sources, keep vapors out of drains and use SCBA in vapor or fire conditions. Cool containers from a protected distance and choose foam, dry chemical or CO2 using SDS and ERG 130.
Firefighter training notes: Training for UN 2402 should emphasize toxic/corrosive exposure, SCBA use, skin-contact prevention, sewer flashback, decontamination, runoff control and foam selection. Use ERG 130, SDS and local SOP.
Regulatory context: Propanethiols is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Propanethiols should be stored in approved flammable/toxic or corrosive-liquid containers with ventilation, secondary containment and separation from heat, ignition sources, oxidizers and incompatible materials.
UN 2402 Quick Details
Common Hazards of UN 2402
- FLAMMABLE sulfur-containing liquid; vapors may ignite and form explosive mixtures with air.
- Strong odor may be noticed at low levels, but odor is not a safe exposure-control method.
- Vapors are heavier than air and may travel to ignition sources and flash back.
- Liquid or vapor may irritate eyes, skin and respiratory tissue.
- Fire may produce sulfur oxides, carbon monoxide and irritating/toxic smoke.
- Runoff to sewers may create fire, explosion and odor/toxic contamination hazards.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a strong, offensive, skunk-like odor. Liquid at room temperature with extremely low odor threshold.
| Also known as | 1-Propanethioln-Propyl mercaptanPropyl mercaptan1-Mercaptopropane |
| CAS Number | 107-03-9 |
| Appearance | Colorless to pale yellow liquid with a strong, offensive, skunk-like odor. Liquid at room temperature with extremely low odor threshold. |
| Flash Point | -20C (-4F) |
| Boiling Point | 67-68C (153-154F) |
| Vapor Density | 2.6 (heavier than air) |
| Water Reactivity | No significant reaction; insoluble in water |
Fireground Response Guidance — UN 2402
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fire or confined-space exposure. Wear chemical-resistant gloves, eye/face protection and flame-resistant protection as appropriate.
Isolation & Evacuation
First Actions for a UN 2402 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream; keep responders out of low vapor areas.
- Eliminate ignition sources if this can be done safely.
- Avoid breathing vapor, mist or smoke and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 130, SDS, shipping papers and air monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2402 — PropanethiolsUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.