UN 1938 — Bromoacetic acid, solution
Placard: Corrosive. ERG Guide 156. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1938 is Bromoacetic acid, solution, a toxic corrosive acid solution assigned to ERG Guide 156. It can cause severe burns and systemic toxicity through skin contact.
Hazard overview: UN 1938 presents toxic corrosive contact, skin absorption, acid runoff and toxic/corrosive fire gas hazards. Prevent contaminated clothing and runoff spread.
Response guidance: For a UN 1938 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 156. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff or vapor spread and choose entry/fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1938 should emphasize exposure routes, air monitoring, PPE selection, decontamination, runoff containment and ERG/SDS verification. Use ERG 156, SDS and local SOP.
Regulatory context: Bromoacetic acid, solution 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: Bromoacetic acid, solution should be stored in tightly closed compatible containers in a secure, cool, dry, well-ventilated hazardous-material area according to SDS and local procedures.
UN 1938 Quick Details
Common Hazards of UN 1938
- TOXIC and CORROSIVE bromoacetic acid solution; inhalation, ingestion or skin contact may cause severe injury.
- Can cause severe burns and systemic toxicity; contaminated clothing can extend exposure.
- Combustible material: may burn under fire conditions.
- Heating or fire may produce hydrogen bromide and other toxic/corrosive gases.
- Runoff may carry acidic brominated contamination.
- Containers may rupture or fail when heated.
- Avoid all skin and eye contact and control runoff.
Chemical Identity & Physical Properties
Colorless to light yellow crystalline solid or solution with a pungent, acrid odor. Highly corrosive and deliquescent (absorbs moisture from air).
| Also known as | Monobromoacetic acidBBAAlpha-bromoacetic acid2-Bromoacetic acidBromoethanoic acid |
| CAS Number | 79-08-3 |
| Appearance | Colorless to light yellow crystalline solid or solution with a pungent, acrid odor. Highly corrosive and deliquescent (absorbs moisture from air). |
| Flash Point | Not applicable (solid); solution flash point varies with concentration and solvent |
| Boiling Point | 208C (406F) - decomposes |
| Vapor Density | 4.8 (heavier than air) |
| Water Reactivity | Reacts slowly with water releasing heat and forming corrosive hydrobromic acid; more vigorous reaction at elevated temperatures |
Fireground Response Guidance — UN 1938
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, mist, fire or confined-space exposure. Chemical-resistant gloves, boots, eye/face protection and protective clothing should be selected from SDS; prevent skin contact.
Isolation & Evacuation
First Actions for a UN 1938 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, smoke or gas and avoid skin or eye contact.
- 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, gas accumulation or unknown concentration is present.
- Use ERG Guide 156, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1938 — Bromoacetic acid, solutionUse 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.