UN 1134 — Chlorobenzene
Placard: Flammable. ERG Guide 130. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1134 is Chlorobenzene, a Class 3 flammable chlorinated liquid assigned to ERG Guide 130. It combines flammable vapor behavior with chlorinated solvent exposure and toxic fire-product concerns.
Hazard overview: UN 1134 presents flammable vapor, flashback and chlorinated solvent hazards. Fire can produce corrosive or toxic decomposition products, and vapors may collect in low or sewer areas where ignition can cause explosion.
Response guidance: For a UN 1134 incident, responders should confirm the product using shipping papers, container markings, SDS and ERG Guide 130. Establish incident command, isolate the area, stay upwind and uphill, remove ignition sources when safe, keep vapors or runoff out of sewers and use compatible Class B fire-control agents from a protected position.
Firefighter training notes: Training for UN 1134 should emphasize flammable vapor behavior, chlorinated solvent exposure, toxic fire products and runoff control. Common errors include relying only on fire PPE, allowing liquid into drains and entering low areas without monitoring.
Regulatory context: Chlorobenzene is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Chlorobenzene should be stored in tightly closed compatible containers in a cool, dry, well-ventilated flammable-liquid storage area. Keep away from heat, sparks, open flames, oxidizers and incompatible materials, with bonding/grounding, secondary containment and drain protection where required.
UN 1134 Quick Details
Common Hazards of UN 1134
- FLAMMABLE chlorinated liquid; vapors may ignite and form explosive mixtures with air.
- Vapors are heavier than air and may collect in low, confined or sewer areas.
- Liquid or vapor may irritate eyes, skin and respiratory tissue.
- Fire may produce irritating, corrosive and/or toxic gases, including hydrogen chloride or phosgene-like decomposition products depending on conditions.
- Runoff to sewer may create fire, explosion or environmental hazards.
- Liquid may be denser than water and may spread below the surface depending on the isomer or mixture.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Clear, colorless liquid with a characteristic almond-like odor. Liquid at room temperature with moderate volatility.
| Also known as | monochlorobenzenephenyl chloridebenzene chlorideMCB |
| CAS Number | 108-90-7 |
| Appearance | Clear, colorless liquid with a characteristic almond-like odor. Liquid at room temperature with moderate volatility. |
| Flash Point | 29°C (84°F) |
| Boiling Point | 132°C (270°F) |
| Vapor Density | 3.9 (heavier than air) |
| Water Reactivity | Insoluble in water; no significant reaction with water |
Fireground Response Guidance — UN 1134
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for fire, vapor or confined-space exposure. Chemical-resistant gloves, splash protection and protective clothing should be selected using SDS because chlorinated solvent liquids and fire products can be harmful.
Isolation & Evacuation
First Actions for a UN 1134 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Eliminate ignition sources if it is safe to do so.
- Do not touch or walk through spilled liquid unless properly trained and wearing appropriate protective equipment.
- Avoid breathing vapors and avoid skin or eye contact with liquid.
- Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
- Isolate the spill or leak area for at least 50 meters (150 feet) in all directions.
- For large spills, fire involvement or strong vapor movement, expand isolation and consider downwind evacuation based on monitoring and incident command.
- Use ERG Guide 130, shipping papers, SDS and local SOP for protective actions and entry decisions.
📋 Copy & Share Field Card
UN 1134 — ChlorobenzeneUse 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.