UN 2668 — Chloroacetonitrile
Placard: Toxic. ERG Guide 131. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2668 is Chloroacetonitrile, a toxic flammable chlorinated nitrile assigned to ERG Guide 131. HCN/HCl fire products and flashback are key concerns.
Hazard overview: TOXIC and FLAMMABLE chlorinated nitrile; inhalation, ingestion or skin absorption may be fatal. Vapors may ignite and form explosive mixtures with air. Vapor or liquid is lachrymatory and can irritate or burn eyes, skin and respiratory tissue.
Response guidance: For UN 2668, isolate the area, avoid skin contact and use SCBA where dust, vapor, mist or fire is present. Control ignition or moisture hazards as applicable and contain toxic/corrosive runoff.
Firefighter training notes: Training for UN 2668 should emphasize toxic exposure routes, SCBA use, dust/vapor monitoring, fire behavior, decontamination, runoff containment and SDS verification. Use ERG 131, SDS and local SOP.
Regulatory context: Chloroacetonitrile 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: Chloroacetonitrile should be stored in tightly closed compatible containers with ventilation, secondary containment, restricted access and SDS-based segregation from incompatible materials.
UN 2668 Quick Details
Common Hazards of UN 2668
- TOXIC and FLAMMABLE chlorinated nitrile; inhalation, ingestion or skin absorption may be fatal.
- Vapors may ignite and form explosive mixtures with air.
- Vapor or liquid is lachrymatory and can irritate or burn eyes, skin and respiratory tissue.
- Water decomposition or fire may release hydrogen cyanide, hydrogen chloride and other toxic/corrosive gases.
- Vapors are heavier than air and may travel to ignition sources and flash back.
- Runoff may be toxic, corrosive and environmentally harmful.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a pungent, irritating odor. Volatile and lachrymatory (causes tearing).
| Also known as | Chloromethyl cyanideMonochloroacetonitrile2-ChloroacetonitrileChloroacetic nitrile |
| CAS Number | 107-14-2 |
| Appearance | Colorless to pale yellow liquid with a pungent, irritating odor. Volatile and lachrymatory (causes tearing). |
| Flash Point | 56°C (133°F) |
| Boiling Point | 124-126°C (255-259°F) |
| Vapor Density | 2.6 (heavier than air) |
| Water Reactivity | Decomposes slowly in water, releasing toxic hydrogen cyanide and corrosive hydrochloric acid vapors |
Fireground Response Guidance — UN 2668
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and full chemical protective clothing. Level A may be needed for heavy vapor, splash risk or unknown concentrations; avoid skin contact.
Isolation & Evacuation
First Actions for a UN 2668 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 2668 — ChloroacetonitrileUse 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.