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 At a Glance
UN 3277 (Chloroformates, poisonous, corrosive) is listed as DOT Class 6 Toxic and is assigned to ERG Guide 154. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
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.