UN 2746 — Phenyl chloroformate
Placard: Toxic. ERG Guide 156. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2746 is Phenyl chloroformate, a toxic corrosive combustible chloroformate assigned to ERG Guide 156. Water reaction and acidic runoff must be controlled.
Hazard overview: TOXIC and CORROSIVE combustible chloroformate liquid; inhalation or skin contact may cause severe injury. Reacts with water or moist air, releasing hydrogen chloride, carbon dioxide, heat and corrosive runoff. Heated vapors may form ignitable mixtures and collect in low or confined areas.
Response guidance: For UN 2746, isolate the spill, stay upwind and use SCBA with chemical protection. Control moisture contact, use compatible dry agents and contain acidic/toxic runoff under SDS and ERG 156.
Firefighter training notes: Training for UN 2746 should emphasize moisture-reactive corrosive fuming, dry-agent choice, SCBA/Level A decisions, decontamination and acidic runoff control. Use ERG 156, SDS and local SOP.
Regulatory context: Phenyl chloroformate 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: Phenyl chloroformate should be stored dry in tightly closed compatible containers away from water, moisture, bases, alcohols, amines, heat and unauthorized access. Provide secondary containment.
UN 2746 Quick Details
Common Hazards of UN 2746
- TOXIC and CORROSIVE combustible chloroformate liquid; inhalation or skin contact may cause severe injury.
- Reacts with water or moist air, releasing hydrogen chloride, carbon dioxide, heat and corrosive runoff.
- Heated vapors may form ignitable mixtures and collect in low or confined areas.
- Vapors may travel to ignition sources and flash back when heated.
- Fire may produce hydrogen chloride, phosgene-type gases and other toxic/corrosive smoke.
- Runoff may be acidic, toxic and environmentally harmful.
- Containers may rupture or fail when heated or contaminated with water.
Chemical Identity & Physical Properties
Clear to pale yellow liquid with a pungent, irritating odor. Combustible liquid at room temperature.
| Also known as | Carbonochloridic acid phenyl esterPhenyl chlorocarbonateChloroformic acid phenyl esterFormic acid chlorophenyl ester |
| CAS Number | 1885-14-9 |
| Appearance | Clear to pale yellow liquid with a pungent, irritating odor. Combustible liquid at room temperature. |
| Flash Point | 107C (225F) |
| Boiling Point | 188C (370F) |
| Vapor Density | 5.4 (heavier than air) |
| Water Reactivity | Reacts with water releasing hydrochloric acid and phenol; produces toxic and corrosive fumes |
Fireground Response Guidance — UN 2746
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and chemical-resistant protective clothing. Level A may be needed for heavy vapor, fuming, splash risk or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 2746 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 because it can release heat and corrosive gases.
- 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 156, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2746 — Phenyl chloroformateUse 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.