UN 2643 — Methyl bromoacetate
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2643 is Methyl bromoacetate, a toxic lachrymator liquid assigned to ERG Guide 153. Eye irritation, skin absorption and brominated fire products are key hazards.
Hazard overview: TOXIC and combustible/flammable lachrymator liquid; inhalation, ingestion or skin absorption may cause severe injury. Vapor or mist can cause intense eye tearing and respiratory irritation. Heated vapors may form explosive mixtures and collect in low or confined areas.
Response guidance: For UN 2643, isolate the area, avoid skin contact and use SCBA where dust, vapor, mist or fire is present. Prevent spread of contaminated runoff, cool containers from protection and verify controls with SDS and ERG 153.
Firefighter training notes: Training for UN 2643 should emphasize toxic exposure routes, skin absorption, SCBA use, dust/vapor control, decontamination, runoff containment and SDS verification. Use ERG 153, SDS and local SOP.
Regulatory context: Methyl bromoacetate 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: Methyl bromoacetate should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and separation from heat, oxidizers and incompatible materials.
UN 2643 Quick Details
Common Hazards of UN 2643
- TOXIC and combustible/flammable lachrymator liquid; inhalation, ingestion or skin absorption may cause severe injury.
- Vapor or mist can cause intense eye tearing and respiratory irritation.
- Heated vapors may form explosive mixtures and collect in low or confined areas.
- Slow hydrolysis in water may form corrosive and toxic bromoacetic acid/methanol-containing runoff.
- Fire may produce hydrogen bromide, bromine-containing fumes and other toxic/corrosive gases.
- Runoff may be toxic, corrosive and environmentally harmful.
- Skin contact and contaminated clothing can extend exposure.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a sharp, pungent, irritating odor. Lachrymator that causes tearing. Denser than water.
| Also known as | Methyl bromoacetateBromoacetic acid methyl esterMethyl monobromoacetateMBA |
| CAS Number | 96-32-2 |
| Appearance | Colorless to pale yellow liquid with a sharp, pungent, irritating odor. Lachrymator that causes tearing. Denser than water. |
| Flash Point | Not available, but considered flammable liquid |
| Boiling Point | 144-145C (291-293F) |
| Vapor Density | 5.3 (heavier than air) |
| Water Reactivity | Slowly hydrolyzes in water, producing corrosive and toxic vapors |
Fireground Response Guidance — UN 2643
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for dust, vapor, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2643 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 153, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2643 — Methyl bromoacetateUse 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.