☣️ UN 1739 • CLASS 8
UN 1739 — Benzyl chloroformate
Placard: Corrosive. ERG Guide 137. 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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UN 1739 Quick Details
UN 1739
Product name: Benzyl chloroformate
DOT Class: 8
Placard type: Corrosive
ERG Guide: 137 (check current ERG)
Initial 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.
Common Hazards of UN 1739
- 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.
Chemical Identity & Physical Properties
| Also known as | Benzyl chlorocarbonateCarbobenzoxy chlorideChloroformic acid benzyl esterBenzyloxycarbonyl chloride |
| CAS Number | 501-53-1 |
| Appearance | Colorless to pale yellow liquid with a pungent, irritating odor. Fuming in moist air. Corrosive to metals and tissues. |
| Flash Point | 100°C (212°F) |
| Boiling Point | 103°C (217°F) |
| Vapor Density | 5.9 (heavier than air) |
| Water Reactivity | Reacts with water to produce hydrochloric acid and carbon dioxide with heat generation. Reaction increases corrosive vapor concentration. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1739
Extinguishing Media
Dry chemical, CO2, or dry sand only. Do not use water or foam directly on liquid.
PPE Requirements
⚠️ Level B minimum required. Full-face SCBA, chemical-resistant suit, gloves, and boots. Avoid all contact with skin and eyes.
Isolation & Evacuation
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.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 137).
First Actions for a UN 1739 Incident
- 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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📋 Copy & Share Field Card
UN 1739 — Benzyl chloroformateHAZMAT 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.
=== 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.
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
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Frequently Asked Questions about UN 1739
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.
Water reactivity: Reacts with water to produce hydrochloric acid and carbon dioxide with heat generation. Reaction increases corrosive vapor concentration.. Recommended extinguishing: Dry chemical, CO2, or dry sand only. Do not use water or foam directly on liquid..
ERG Guide 137 recommendation: 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.
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.