☣️ UN 1611 • CLASS 6
UN 1611 — Hexaethyl tetraphosphate
Placard: Toxic. ERG Guide 151. 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 1611 Quick Details
UN 1611
Product name: Hexaethyl tetraphosphate
DOT Class: 6
Placard type: Toxic
ERG Guide: 151 (check current ERG)
Initial isolation: ERG 151: isolate spill 25-50m; initial evacuation 100m downwind; if tank/rail car involved, isolate 800m all directions
Common Hazards of UN 1611
- Highly toxic, may be fatal if inhaled, ingested or absorbed through skin.
- Avoid any skin contact.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
- Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive
- Containers may explode when heated.
- Runoff may pollute waterways.
Chemical Identity & Physical Properties
| Also known as | HETPTetraphosphoric acid hexaethyl esterBladanHexaethyl tetraphosphate |
| CAS Number | 757-58-4 |
| Appearance | Colorless to amber-colored liquid with a faint, pleasant odor. Oily consistency at room temperature. |
| Flash Point | Not readily flammable under normal conditions |
| Boiling Point | Decomposes before boiling at approximately 150C (302F) |
| Vapor Density | Not applicable (low volatility liquid) |
| Water Reactivity | Hydrolyzes slowly in water; no violent reaction but produces toxic degradation products |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1611
Extinguishing Media
Alcohol-resistant foam, CO2, dry chemical suitable; avoid high-pressure water streams
PPE Requirements
⚠️ Level A required; SCBA and fully encapsulating chemical-resistant suit mandatory; extreme skin absorption hazard
Isolation & Evacuation
ERG 151: isolate spill 25-50m; initial evacuation 100m downwind; if tank/rail car involved, isolate 800m all directions
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 151).
First Actions for a UN 1611 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.
- 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 1611 — Hexaethyl tetraphosphateHAZMAT RADIO NOTE — UN 1611
Product: Hexaethyl tetraphosphate
Class 6 / Toxic / ERG 151
PPE: Level A required; SCBA and fully encapsulating chemical-resistant suit mandatory; extreme skin absorption hazard
ISOLATION: ERG 151: isolate spill 25-50m; initial evacuation 100m downwind; if tank/rail car involved, isolate 800m all directions
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 1611 — Hexaethyl tetraphosphate
Class: 6 | Placard: Toxic | ERG Guide: 151
Appearance: Colorless to amber-colored liquid with a faint, pleasant odor. Oily consistency at room temperature.
Water Reactivity: Hydrolyzes slowly in water; no violent reaction but produces toxic degradation products
Extinguishing: Alcohol-resistant foam, CO2, dry chemical suitable; avoid high-pressure water streams
PPE: Level A required; SCBA and fully encapsulating chemical-resistant suit mandatory; extreme skin absorption hazard
Isolation: ERG 151: isolate spill 25-50m; initial evacuation 100m downwind; if tank/rail car involved, isolate 800m all directions
— Key Hazards —
• Highly toxic, may be fatal if inhaled, ingested or absorbed through skin.
• Avoid any skin contact.
• Fire may produce irritating, corrosive and/or toxic gases.
— 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.
• Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
SOURCE: allfirefighter.com/hazmat/un/1611 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN1611 Hexaethyl tetraphosphate Cls6 ERG151 | allfirefighter.com/hazmat/un/1611SMS / 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/1611
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Frequently Asked Questions about UN 1611
Highly toxic, may be fatal if inhaled, ingested or absorbed through skin. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive Containers may explode when heated. Runoff may pollute waterways.
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; SCBA and fully encapsulating chemical-resistant suit mandatory; extreme skin absorption hazard
Water reactivity: Hydrolyzes slowly in water; no violent reaction but produces toxic degradation products. Recommended extinguishing: Alcohol-resistant foam, CO2, dry chemical suitable; avoid high-pressure water streams.
ERG Guide 151 recommendation: ERG 151: isolate spill 25-50m; initial evacuation 100m downwind; if tank/rail car involved, isolate 800m all directions
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 151 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.