UN 1891 — Ethyl bromide
Placard: Toxic. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1891 is Ethyl bromide, a toxic highly flammable liquid assigned to ERG Guide 131. Vapors can flash back and also create serious inhalation and skin exposure hazards.
Hazard overview: UN 1891 presents toxic vapor, skin absorption, flammable vapor, flashback and sewer explosion hazards. Fire may produce hydrogen bromide and other toxic gases.
Response guidance: For a UN 1891 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 131. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1891 should emphasize toxic solvent vapor behavior, low-area accumulation, skin exposure, decomposition gas hazards, air monitoring and runoff containment. Use ERG 131, SDS and local SOP.
Regulatory context: Ethyl bromide 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, concentration, 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: Ethyl bromide should be stored in tightly closed compatible containers in a cool, well-ventilated toxic-solvent area away from heat, ignition sources where applicable, strong oxidizers, reactive metals where incompatible and drains.
UN 1891 Quick Details
Common Hazards of UN 1891
- TOXIC and HIGHLY FLAMMABLE liquid; inhalation, ingestion or skin absorption may cause serious injury.
- Vapors may form explosive mixtures with air and travel to ignition sources.
- Vapors are heavier than air and may collect in low or confined areas.
- Contact may irritate or burn eyes and skin.
- Fire may produce hydrogen bromide and other toxic/corrosive gases.
- Runoff to sewers may create fire, explosion and contamination hazards.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Colorless to yellowish liquid with a sweet, chloroform-like odor. Volatile and readily vaporizes at room temperature.
| Also known as | BromoethaneMonobromoethaneEthyl bromideHalon 2001 |
| CAS Number | 74-96-4 |
| Appearance | Colorless to yellowish liquid with a sweet, chloroform-like odor. Volatile and readily vaporizes at room temperature. |
| Flash Point | -23°C (-9°F) |
| Boiling Point | 38°C (100°F) |
| Vapor Density | 3.7 (heavier than air) |
| Water Reactivity | No significant reaction with water; slightly soluble |
Fireground Response Guidance — UN 1891
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fire or confined-space exposure. Chemical-resistant gloves, eye/face protection and protective clothing should be selected from SDS to prevent solvent skin contact.
Isolation & Evacuation
First Actions for a UN 1891 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.
- Avoid breathing vapors, fumes, dust, mist or spray and avoid skin or eye contact.
- Eliminate ignition sources if safe and keep vapors out of drains, sewers and low areas.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if vapor, dust, fire involvement, water reaction or unknown concentration is present.
- Use ERG Guide 131, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1891 — Ethyl bromideUse 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.