☣️ UN 1739 • CLASS 8

Benzyl chloroformate

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

🚒☣️
⚠️ 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 1739
Class: 8
Placard type: Corrosive
ERG: Guide 137 (check current ERG)
Isolation: ERG 137: Isolate spill area immediately for at least 50m in all directions. If tank/rail car involved in fire, isolate 800m in all directions and evacuate.
Chemical & Response Details
Also known asBenzyl chlorocarbonateCarbobenzoxy chlorideChloroformic acid benzyl esterBenzyloxycarbonyl chloride
CAS Number501-53-1
AppearanceColorless to pale yellow liquid with a pungent, irritating odor. Fuming in moist air. Corrosive to metals and tissues.
Flash Point100°C (212°F)
Boiling Point103°C (217°F)
Vapor Density5.9 (heavier than air)
Water ReactivityReacts with water to produce hydrochloric acid and carbon dioxide with heat generation. Reaction increases corrosive vapor concentration.
ExtinguishingDry chemical, CO2, or dry sand only. Do not use water or foam directly on liquid.
PPE⚠️ Level B minimum required. Full-face SCBA, chemical-resistant suit, gloves, and boots. Avoid all contact with skin and eyes.
IsolationERG 137: Isolate spill area immediately for at least 50m in all directions. If tank/rail car involved in fire, isolate 800m in all directions and evacuate.
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
  • Fire will produce irritating, corrosive and/or toxic gases.
  • Reaction with water may generate much heat that will increase the concentration of fumes in the air.
  • Contact with molten substance may cause severe burns to skin and eyes.
  • Runoff from fire control or dilution water may cause environmental contamination.
  • EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may
  • May ignite combustibles (wood, paper, oil, clothing, etc.).
  • Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff.
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 1739 — Benzyl chloroformate
HAZMAT RADIO NOTE — UN 1739 Product: Benzyl chloroformate Class 8 / Corrosive / ERG 137 PPE: Level B minimum required. Full-face SCBA, chemical-resistant suit, gloves, and boots. Avoid all contact with skin and eyes. ISOLATION: ERG 137: Isolate spill area immediately for at least 50m in all directions. If tank/rail car involved in fire, isolate 800m in all directions and evacuate. 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 1739 — Benzyl chloroformate Class: 8 | Placard: Corrosive | ERG Guide: 137 Appearance: Colorless to pale yellow liquid with a pungent, irritating odor. Fuming in moist air. Corrosive to metals and tissues. Water Reactivity: Reacts with water to produce hydrochloric acid and carbon dioxide with heat generation. Reaction increases corrosive vapor concentration. Extinguishing: Dry chemical, CO2, or dry sand only. Do not use water or foam directly on liquid. PPE: Level B minimum required. Full-face SCBA, chemical-resistant suit, gloves, and boots. Avoid all contact with skin and eyes. Isolation: ERG 137: Isolate spill area immediately for at least 50m in all directions. If tank/rail car involved in fire, isolate 800m in all directions and evacuate. — Key Hazards — • CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance • Fire will produce irritating, corrosive and/or toxic gases. • Reaction with water may generate much heat that will increase the concentration of fumes in the air. — 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/1739 | 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)
UN1739 Benzyl chloroformate Cls8 ERG137 | ERG 137: Isolate spill area immediately for at least 50m in all directions. If t | allfirefighter.com/hazmat/un/1739SMS / 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/1739
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

CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance Fire will produce irritating, corrosive and/or toxic gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control or dilution water may cause environmental contamination. EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may May ignite combustibles (wood, paper, oil, clothing, etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff.

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 required. Full-face SCBA, chemical-resistant suit, gloves, and boots. Avoid all contact with skin and eyes.

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 137 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.