UN 1164 — Dimethyl sulphide
Placard: Flammable. ERG Guide 130. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Dimethyl sulphide is a highly flammable and volatile liquid with a strong, disagreeable odor. It is used in various industrial applications, including as a solvent and in the manufacture of other chemicals.
Hazard overview: The substance is highly flammable and can be easily ignited by heat, sparks, or flames, and its vapors may form explosive mixtures with air. Prolonged exposure to the substance can cause irritation to the skin, eyes, and respiratory system.
Response guidance: In case of an emergency, evacuate the area immediately and call for professional help. Wear Level B minimum protective gear, including a self-contained breathing apparatus and chemical-resistant suit, to minimize exposure to the substance and its vapors.
UN 1164 Quick Details
Common Hazards of UN 1164
- HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
- Vapors may form explosive mixtures with air.
- Vapors may travel to source of ignition and flash back.
- Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
- Vapor explosion hazard indoors, outdoors or in sewers.
- Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
- Runoff to sewer may create fire or explosion hazard.
- Containers may explode when heated.
Chemical Identity & Physical Properties
Dimethyl sulphide is a colorless to pale yellow liquid with a strong, disagreeable odor resembling decayed cabbage or garlic, and it is highly volatile at room temperature.
| Also known as | DMSMethyl sulfide2-ThiapropaneDimethyl thioetherMethyl monosulfide |
| CAS Number | 75-18-3 |
| Appearance | Colorless to pale yellow liquid with a strong, disagreeable odor resembling decayed cabbage or garlic. Highly volatile at room temperature. |
| Flash Point | -37°C (-35°F) |
| Boiling Point | 37°C (99°F) |
| Vapor Density | 2.1 (heavier than air) |
| Water Reactivity | No significant reaction with water; slightly soluble |
Fireground Response Guidance — UN 1164
Extinguishing Media
PPE Requirements
Level B minimum protective gear, including a self-contained breathing apparatus and chemical-resistant suit, is recommended to handle the substance due to its strong odor and vapor hazard.
Isolation & Evacuation
First Actions for a UN 1164 Incident
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area for at least 50 meters (150 feet) in all directions.
- Consider initial downwind evacuation for at least 300 meters (1000 feet).
📋 Copy & Share Field Card
UN 1164 — Dimethyl sulphideUse 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.