☣️ UN 1758 • CLASS 8
UN 1758 — Chromium oxychloride
Placard: Corrosive. ERG Guide 137. 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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UN 1758 Quick Details
UN 1758
Product name: Chromium oxychloride
DOT Class: 8
Placard type: Corrosive
ERG Guide: 137 (check current ERG)
Initial isolation: ERG 137: isolate spill 50m all directions; initial evacuation 100m all directions, increase if fire or water contact occurs
Common Hazards of UN 1758
- 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 | Chromyl chlorideChromium dichloride dioxideChromic oxychlorideChlorochromic anhydride |
| CAS Number | 14977-61-8 |
| Appearance | Dark red to brownish-red fuming liquid with a pungent, acrid odor. Forms dense reddish-brown vapors in moist air due to hydrolysis. |
| Flash Point | Not applicable (non-flammable oxidizer) |
| Boiling Point | 117C (243F) |
| Vapor Density | 5.3 (heavier than air) |
| Water Reactivity | Reacts violently with water producing heat, hydrochloric acid fumes, and chromic acid; extreme corrosive hazard |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1758
Extinguishing Media
Dry chemical, CO2, sand only; do not use water or foam due to violent reactivity
PPE Requirements
⚠️ Level A required; full face SCBA, acid-resistant suit; chromium VI compounds are carcinogenic and highly corrosive
Isolation & Evacuation
ERG 137: isolate spill 50m all directions; initial evacuation 100m all directions, increase if fire or water contact occurs
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 137).
First Actions for a UN 1758 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 1758 — Chromium oxychlorideHAZMAT RADIO NOTE — UN 1758
Product: Chromium oxychloride
Class 8 / Corrosive / ERG 137
PPE: Level A required; full face SCBA, acid-resistant suit; chromium VI compounds are carcinogenic and highly corrosive
ISOLATION: ERG 137: isolate spill 50m all directions; initial evacuation 100m all directions, increase if fire or water contact occurs
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 1758 — Chromium oxychloride
Class: 8 | Placard: Corrosive | ERG Guide: 137
Appearance: Dark red to brownish-red fuming liquid with a pungent, acrid odor. Forms dense reddish-brown vapors in moist air due to hydrolysis.
Water Reactivity: Reacts violently with water producing heat, hydrochloric acid fumes, and chromic acid; extreme corrosive hazard
Extinguishing: Dry chemical, CO2, sand only; do not use water or foam due to violent reactivity
PPE: Level A required; full face SCBA, acid-resistant suit; chromium VI compounds are carcinogenic and highly corrosive
Isolation: ERG 137: isolate spill 50m all directions; initial evacuation 100m all directions, increase if fire or water contact occurs
— 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/1758 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1758 Chromium oxychloride Cls8 ERG137 | ERG 137: isolate spill 50m all directions; initial evacuation 100m all direction | allfirefighter.com/hazmat/un/1758SMS / 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/1758
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Frequently Asked Questions about UN 1758
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 A required; full face SCBA, acid-resistant suit; chromium VI compounds are carcinogenic and highly corrosive
Water reactivity: Reacts violently with water producing heat, hydrochloric acid fumes, and chromic acid; extreme corrosive hazard. Recommended extinguishing: Dry chemical, CO2, sand only; do not use water or foam due to violent reactivity.
ERG Guide 137 recommendation: ERG 137: isolate spill 50m all directions; initial evacuation 100m all directions, increase if fire or water contact occurs
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.