UN 2840 — Butyraldoxime
Placard: Flammable. ERG Guide 129. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2840 is Butyraldoxime, a flammable oxime liquid assigned to ERG Guide 129. Vapor flashback and NOx fire products are key concerns.
Hazard overview: FLAMMABLE oxime liquid; vapors may ignite and form explosive mixtures with air. Vapors are heavier than air and may travel to ignition sources and flash back. Vapor explosion hazard exists in drains, sewers, basements and confined areas.
Response guidance: For UN 2840, isolate the area, eliminate ignition sources and use SCBA. Keep vapors out of drains, cool containers from protection and use foam, dry chemical or CO2 per SDS.
Firefighter training notes: Training for UN 2840 should emphasize exposure routes, SCBA use, vapor/dust monitoring, fire behavior, decontamination, runoff containment and SDS verification. Use ERG 129, SDS and local SOP.
Regulatory context: Butyraldoxime 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: Butyraldoxime should be stored in approved flammable-liquid containers with ventilation, secondary containment and separation from heat, ignition sources, oxidizers and incompatible materials.
UN 2840 Quick Details
Common Hazards of UN 2840
- FLAMMABLE oxime liquid; vapors may ignite and form explosive mixtures with air.
- Vapors are heavier than air and may travel to ignition sources and flash back.
- Vapor explosion hazard exists in drains, sewers, basements and confined areas.
- Liquid and vapor may irritate eyes, skin and respiratory tract.
- Heating or decomposition may produce nitrogen oxides and irritating/toxic smoke.
- Runoff to sewers may create fire or explosion hazards.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a characteristic oxime odor. Liquid at room temperature.
| Also known as | Butanal oximen-Butyraldehyde oximeButanal, oximeButyraldoxime1-Butanal oxime |
| CAS Number | 110-69-0 |
| Appearance | Colorless to pale yellow liquid with a characteristic oxime odor. Liquid at room temperature. |
| Flash Point | 58°C (136°F) |
| Boiling Point | 152°C (306°F) |
| Vapor Density | 3.0 (heavier than air) |
| Water Reactivity | Low water solubility, no significant violent reaction with water |
Fireground Response Guidance — UN 2840
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 2840 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.
- Eliminate ignition sources if this can be done safely.
- 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 liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 129, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2840 — ButyraldoximeUse 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.