UN 1722 — Allyl chlorocarbonate
Placard: Toxic. ERG Guide 155. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1722 is Allyl chlorocarbonate, a highly flammable toxic chloroformate assigned to ERG Guide 155. It can release corrosive hydrogen chloride fumes on contact with moisture.
Hazard overview: UN 1722 presents flammable vapor, toxic inhalation, corrosive fume and water-reactivity hazards. Vapors can flash back, and runoff may become corrosive and toxic.
Response guidance: For a UN 1722 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 155. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1722 should emphasize water-reactive corrosive fumes, dry-agent selection, vapor control, ignition control where relevant, runoff containment and decontamination. Use ERG 155, SDS and local SOP.
Regulatory context: Allyl chlorocarbonate is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by concentration, formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Allyl chlorocarbonate should be stored in tightly closed compatible containers in a cool, dry, well-ventilated area away from water, moisture, bases, oxidizers, ignition sources where relevant and unauthorized access. Protect containers from corrosion, leakage and contamination.
UN 1722 Quick Details
Common Hazards of UN 1722
- HIGHLY FLAMMABLE and TOXIC liquid; vapors may ignite easily and flash back.
- Reacts with water or moisture to release corrosive hydrogen chloride and other toxic fumes.
- Vapors form explosive mixtures with air and can accumulate in sewers or low areas.
- Inhalation, ingestion or skin contact may cause severe injury.
- Fire may produce irritating, corrosive and/or toxic gases.
- Containers may rupture or explode when heated or contaminated with water.
- Runoff may be corrosive, toxic and flammable.
Chemical Identity & Physical Properties
Colorless to pale yellow liquid with a pungent, irritating odor. Liquid at room temperature with corrosive properties.
| Also known as | Allyl chloroformateChloroformic acid allyl esterCarbonochloridic acid 2-propenyl ester2-Propenyl chloroformate |
| CAS Number | 2937-50-0 |
| Appearance | Colorless to pale yellow liquid with a pungent, irritating odor. Liquid at room temperature with corrosive properties. |
| Flash Point | 32°F (0°C) |
| Boiling Point | 230°F (110°C) |
| Vapor Density | 4.2 (heavier than air) |
| Water Reactivity | Reacts with water releasing toxic and corrosive hydrochloric acid fumes; avoid direct water contact |
Fireground Response Guidance — UN 1722
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fume, fire or confined-space exposure. Chemical-resistant gloves, boots, eye/face protection and protective clothing should be selected from SDS; Level A may be needed for close entry or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 1722 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, fumes, dust or mist and avoid skin or eye contact.
- Eliminate ignition sources if it is safe to do so and keep vapors out of drains, sewers and low areas.
- Keep water and moisture away from the released product unless incident command confirms a compatible cooling or control use.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if vapor, dust, fire involvement, water reaction or unknown concentration is present.
- Use ERG Guide 155, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1722 — Allyl chlorocarbonateUse 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.