UN 2504 — Acetylene tetrabromide
Placard: Toxic. ERG Guide 159. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2504 At a Glance
UN 2504 (Acetylene tetrabromide) is listed as DOT Class 6 Toxic and is assigned to ERG Guide 159. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.