UN 2504 — Acetylene tetrabromide
Placard: Toxic. ERG Guide 159. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2504 is Acetylene tetrabromide, a toxic dense halogenated liquid assigned to ERG Guide 159. It may sink in water and spread contamination.
Hazard overview: TOXIC halogenated liquid; inhalation, ingestion or skin contact may cause severe injury. Combustible material: may burn but does not ignite readily. Vapors are very heavy and may collect in low or confined areas.
Response guidance: For UN 2504, isolate the area, avoid skin contact and use SCBA where vapor, dust, mist or fire is present. Contain toxic/corrosive runoff and verify product controls with SDS and ERG 159.
Firefighter training notes: Training for UN 2504 should emphasize toxic/corrosive exposure routes, skin absorption, SCBA use, decontamination, runoff containment and SDS verification. Use ERG 159, SDS and local SOP.
Regulatory context: Acetylene tetrabromide 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: Acetylene tetrabromide should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 2504 Quick Details
Common Hazards of UN 2504
- TOXIC halogenated liquid; inhalation, ingestion or skin contact may cause severe injury.
- Combustible material: may burn but does not ignite readily.
- Vapors are very heavy and may collect in low or confined areas.
- Liquid is much denser than water and may sink, spreading contamination below the surface.
- Fire may produce hydrogen bromide, bromine-containing fumes and other toxic/corrosive gases.
- Runoff may carry persistent brominated contamination.
- Avoid skin contact and prevent spread into drains or waterways.
Chemical Identity & Physical Properties
Colorless to pale yellow heavy liquid with a sweet, chloroform-like odor. Denser than water and practically insoluble in water.
| Also known as | Tetrabromoethane1,1,2,2-TetrabromoethaneTBEMuthmann's liquidSym-tetrabromoethane |
| CAS Number | 79-27-6 |
| Appearance | Colorless to pale yellow heavy liquid with a sweet, chloroform-like odor. Denser than water and practically insoluble in water. |
| Flash Point | Not applicable (non-flammable) |
| Boiling Point | 151C (304F) |
| Vapor Density | 11.6 (much heavier than air) |
| Water Reactivity | No significant reaction with water; insoluble but stable |
Fireground Response Guidance — UN 2504
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2504 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.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated dust, liquid, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 159, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2504 — Acetylene tetrabromideUse 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.