UN 2402 — Propanethiols
Placard: Flammable. ERG Guide 130. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2402 At a Glance
UN 2402 (Propanethiols) is listed as DOT Class 3 Flammable and is assigned to ERG Guide 130. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.