UN 3273 — Nitriles, flammable, poisonous, n.o.s.
Placard: Flammable. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3273 is Nitriles, flammable, poisonous, n.o.s., a broad toxic flammable nitrile entry assigned to ERG Guide 131. Skin absorption, flashback and cyanide-type fire products matter.
Hazard overview: TOXIC and FLAMMABLE nitrile liquid, n.o.s.; inhalation, ingestion or skin absorption may be fatal. Vapors may ignite and form explosive mixtures with air. Vapors are heavier than air and may travel to ignition sources and flash back.
Response guidance: For UN 3273, 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 3273 should emphasize product verification, SCBA use, vapor/dust monitoring, fire behavior, decontamination and runoff control. Use ERG 131, SDS and local SOP.
Regulatory context: Nitriles, flammable, poisonous, 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: Nitriles, flammable, poisonous, 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 3273 Quick Details
Common Hazards of UN 3273
- TOXIC and FLAMMABLE nitrile liquid, n.o.s.; inhalation, ingestion or skin absorption may be fatal.
- Vapors may ignite and form explosive mixtures with air.
- Vapors are heavier than air and may travel to ignition sources and flash back.
- Some nitriles can release hydrogen cyanide, nitrogen oxides or corrosive gases in fire.
- Skin contact and contaminated clothing can extend toxic exposure.
- Runoff may carry toxic nitrile contamination and harm waterways.
- Exact nitrile, solvent and concentration must be verified from SDS.
Chemical Identity & Physical Properties
Variable appearance depending on specific nitrile; typically clear to pale yellow liquids with pungent, irritating odors. Room temperature liquids with characteristic sharp, acrid smell.
| Also known as | Flammable toxic nitrilesPoisonous nitrile compoundsNitrile liquids (flammable/toxic)N.O.S. nitrile solutions |
| Appearance | Variable appearance depending on specific nitrile; typically clear to pale yellow liquids with pungent, irritating odors. Room temperature liquids with characteristic sharp, acrid smell. |
| Flash Point | Varies by specific nitrile; typically below 23°C (73°F) for Class 3 flammable liquids |
| Boiling Point | Varies widely; typically 80-200°C (176-392°F) depending on molecular weight |
| Vapor Density | Greater than 1 (heavier than air); specific values range from 1.4 to 3+ depending on compound |
| Water Reactivity | Generally stable in water; some nitriles may hydrolyze slowly to carboxylic acids and ammonia |
Fireground Response Guidance — UN 3273
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, mist, smoke or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 3273 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 3273 — Nitriles, flammable, poisonous, n.o.s.Use 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.