UN 3277 — Chloroformates, poisonous, corrosive, n.o.s.
Placard: Toxic. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3277 is Chloroformates, poisonous, corrosive, n.o.s., a broad toxic corrosive chloroformate entry assigned to ERG Guide 154. Moisture reaction and HCl fuming are key hazards.
Hazard overview: TOXIC and CORROSIVE chloroformate entry, n.o.s.; inhalation or skin contact may cause severe injury. Reacts with water or moist air, releasing hydrogen chloride, carbon dioxide, heat and corrosive fumes. Many chloroformates are combustible or flammable; vapors may collect in low areas.
Response guidance: For UN 3277, isolate the spill, avoid splash/mist exposure and use SCBA with chemical protection. Control water/neutralization hazards and contain corrosive runoff under ERG 154.
Firefighter training notes: Training for UN 3277 should emphasize corrosive splash/mist control, water/neutralization heat, incompatible materials, SCBA use and runoff containment. Use ERG 154, SDS and local SOP.
Regulatory context: Chloroformates, poisonous, corrosive, 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: Chloroformates, poisonous, corrosive, n.o.s. should be stored in tightly closed compatible containers away from moisture, heat, ignition sources and incompatible acids/bases/oxidizers as specified by SDS.
UN 3277 Quick Details
Common Hazards of UN 3277
- TOXIC and CORROSIVE chloroformate entry, n.o.s.; inhalation or skin contact may cause severe injury.
- Reacts with water or moist air, releasing hydrogen chloride, carbon dioxide, heat and corrosive fumes.
- Many chloroformates are combustible or flammable; vapors may collect in low areas.
- Liquid and vapor can burn eyes, skin and respiratory tissue.
- Fire may produce hydrogen chloride, phosgene-type gases and other toxic/corrosive smoke.
- Runoff may be acidic, toxic and corrosive.
- Exact chloroformate controls flammability, toxicity and water reaction severity.
Chemical Identity & Physical Properties
Colorless to pale yellow liquids with pungent, acrid odor. Corrosive and toxic liquids that may fume in moist air.
| Also known as | Chloroformate estersChlorocarbonic acid estersChloroformiate compoundsCarbonic chloride esters |
| Appearance | Colorless to pale yellow liquids with pungent, acrid odor. Corrosive and toxic liquids that may fume in moist air. |
| Flash Point | Varies by specific chloroformate; typically -7°C to 16°C (19°F to 61°F), highly flammable |
| Boiling Point | Varies by specific chloroformate; typically 50°C to 130°C (122°F to 266°F) |
| Vapor Density | Greater than 1 (heavier than air); vapors will accumulate in low areas |
| Water Reactivity | Reacts with water to release toxic and corrosive HCl gas; hydrolyzes readily in moisture |
Fireground Response Guidance — UN 3277
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, mist, fire or confined-space exposure. Wear chemical-resistant splash suit, gloves, boots and eye/face protection.
Isolation & Evacuation
First Actions for a UN 3277 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.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Keep water or moisture contact controlled until the exact product compatibility is verified.
- 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 154, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3277 — Chloroformates, poisonous, corrosive, n.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.