UN 3279 — Organophosphorus compound, poisonous, flammable, n.o.s.
Placard: Toxic. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3279 is Organophosphorus compound, poisonous, flammable, n.o.s., a broad toxic flammable organophosphorus entry assigned to ERG Guide 131. Solvent flashback and dermal toxicity are key.
Hazard overview: TOXIC and FLAMMABLE organophosphorus compound, n.o.s.; inhalation, ingestion or skin absorption may be fatal. Vapors may ignite and form explosive mixtures with air. Skin contact and contaminated clothing can extend toxic exposure.
Response guidance: For UN 3279, isolate the area, eliminate ignition sources and keep vapors out of drains. Use SCBA, contain runoff and select foam/dry chemical/CO2 using SDS and ERG 131.
Firefighter training notes: Training for UN 3279 should emphasize high-toxicity exposure routes, skin absorption, SCBA/Level A decisions, decontamination, runoff control and exact-compound verification. Use ERG 131, SDS and local SOP.
Regulatory context: Organophosphorus compound, poisonous, flammable, n.o.s. is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, composition, concentration and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Organophosphorus compound, poisonous, flammable, n.o.s. should be stored in approved flammable-liquid containers with ventilation, ignition control, secondary containment and segregation from oxidizers and incompatible materials.
UN 3279 Quick Details
Common Hazards of UN 3279
- TOXIC and FLAMMABLE organophosphorus compound, n.o.s.; inhalation, ingestion or skin absorption may be fatal.
- Vapors may ignite and form explosive mixtures with air.
- Skin contact and contaminated clothing can extend toxic exposure.
- Some compounds may inhibit cholinesterase; exact product identity is critical.
- Fire may produce phosphorus oxides and irritating/toxic gases.
- Runoff may be toxic, flammable-contaminated and environmentally harmful.
- Exact organophosphorus compound, solvent and concentration must be verified from SDS.
Chemical Identity & Physical Properties
Variable appearance depending on specific compound; typically colorless to pale yellow liquid with mild to pungent odor. This is a generic category covering various organophosphorus compounds.
| Also known as | Organophosphorus poisonOrganophosphate compoundPhosphorus-containing toxic substanceOP compound n.o.s. |
| Appearance | Variable appearance depending on specific compound; typically colorless to pale yellow liquid with mild to pungent odor. This is a generic category covering various organophosphorus compounds. |
| Flash Point | Variable, typically 23°C to 61°C (73°F to 142°F) depending on specific compound |
| Boiling Point | Variable, typically 100°C to 300°C (212°F to 572°F) depending on specific compound |
| Vapor Density | Typically >1 (heavier than air) for most organophosphorus liquids |
| Water Reactivity | Some compounds may hydrolyze slowly in water; generally no violent reaction but may release toxic vapors |
Fireground Response Guidance — UN 3279
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and full chemical protective clothing. Level A may be needed for unknown concentration, heavy vapor, splash or high skin-absorption risk.
Isolation & Evacuation
First Actions for a UN 3279 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 131, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3279 — Organophosphorus compound, poisonous, flUse 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.