☣️ UN 2740 • CLASS 6

n-Propyl chloroformate

Placard: Toxic. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

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⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
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Quick details
UN 2740
Class: 6
Placard type: Toxic
ERG: Guide 155 (check current ERG)
Isolation: ERG 155: Isolate spill 50m in all directions. Evacuate 300m downwind if tank/rail car involved in fire.
Chemical & Response Details
Also known aspropyl chlorocarbonatepropyl chloroformatechloroformic acid propyl estercarbonochloridic acid propyl ester
CAS Number109-61-5
AppearanceColorless to pale yellow liquid with a pungent, irritating odor. Fuming liquid that reacts with moisture in air.
Flash Point15°C (59°F)
Boiling Point105-107°C (221-225°F)
Vapor Density4.2 (heavier than air)
Water ReactivityReacts violently with water, liberating HCl and CO2. Do not use water directly on material.
ExtinguishingDry chemical, CO2, or dry sand. Alcohol-resistant foam may be used at a distance. Avoid water spray directly on liquid.
PPE⚠️ Level B minimum recommended. Full-face SCBA, chemical-resistant suit. Material is corrosive and toxic by inhalation.
IsolationERG 155: Isolate spill 50m in all directions. Evacuate 300m downwind if tank/rail car involved in fire.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
  • Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards.
  • Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
  • Vapors may travel to source of ignition and flash back.
  • Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
  • Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff.
  • Corrosives in contact with metals may evolve flammable hydrogen gas.
  • Containers may explode when heated or if contaminated with water.
First actions (field-minded)
  • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
  • Keep unauthorized personnel away.
  • Stay upwind, uphill and/or upstream.
  • Ventilate closed spaces before entering, but only if properly trained and equipped.
  • Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
  • For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
  • For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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UN 2740 — n-Propyl chloroformate
HAZMAT RADIO NOTE — UN 2740 Product: n-Propyl chloroformate Class 6 / Toxic / ERG 155 PPE: Level B minimum recommended. Full-face SCBA, chemical-resistant suit. Material is corrosive and toxic by inhalation. ISOLATION: ERG 155: Isolate spill 50m in all directions. Evacuate 300m downwind if tank/rail car involved in fire. ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 2740 — n-Propyl chloroformate Class: 6 | Placard: Toxic | ERG Guide: 155 Appearance: Colorless to pale yellow liquid with a pungent, irritating odor. Fuming liquid that reacts with moisture in air. Water Reactivity: Reacts violently with water, liberating HCl and CO2. Do not use water directly on material. Extinguishing: Dry chemical, CO2, or dry sand. Alcohol-resistant foam may be used at a distance. Avoid water spray directly on liquid. PPE: Level B minimum recommended. Full-face SCBA, chemical-resistant suit. Material is corrosive and toxic by inhalation. Isolation: ERG 155: Isolate spill 50m in all directions. Evacuate 300m downwind if tank/rail car involved in fire. — Key Hazards — • HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. • Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. • Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas — First Actions — • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper • Keep unauthorized personnel away. • Stay upwind, uphill and/or upstream. • Ventilate closed spaces before entering, but only if properly trained and equipped. SOURCE: allfirefighter.com/hazmat/un/2740 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN2740 n-Propyl chloroformate Cls6 ERG155 | ERG 155: Isolate spill 50m in all directions. Evacuate 300m downwind if tank/rai | allfirefighter.com/hazmat/un/2740SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/2740
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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FAQ

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas Vapors may travel to source of ignition and flash back. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.

Level B minimum recommended. Full-face SCBA, chemical-resistant suit. Material is corrosive and toxic by inhalation.

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 155 and your department SOP/SOG for incident-specific protective actions.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles. This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.