☣️ UN 2781 • CLASS 6
UN 2781 — Bipyridilium pesticide, solid, poisonous
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 2781 Quick Details
UN 2781
Product name: Bipyridilium pesticide, solid, poisonous
DOT Class: 6
Placard type: Toxic
ERG Guide: 151 (check current ERG)
Initial isolation: ERG 151: isolate spill 25m all directions; protective action distance 100m downwind during spill; if fire involves large quantities, isolate 800m all directions
Common Hazards of UN 2781
- 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 | DiquatParaquatBipyridinium herbicideDipyridyl pesticideQuaternary ammonium herbicide |
| Appearance | Typically appears as white to tan or yellowish crystalline solid or granular powder. Odorless or slight characteristic odor. Solid at room temperature. |
| Flash Point | Not applicable (non-flammable solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water; no significant reaction with water |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 2781
Extinguishing Media
Use dry chemical, CO2, water spray, or foam for surrounding fires
PPE Requirements
⚠️ Level A or B required; full chemical protective suit, SCBA mandatory; avoid all skin contact; highly toxic by all routes of exposure
Isolation & Evacuation
ERG 151: isolate spill 25m all directions; protective action distance 100m downwind during spill; if fire involves large quantities, 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 2781 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 2781 — Bipyridilium pesticide, solid, poisonousHAZMAT RADIO NOTE — UN 2781
Product: Bipyridilium pesticide, solid, poisonous
Class 6 / Toxic / ERG 151
PPE: Level A or B required; full chemical protective suit, SCBA mandatory; avoid all skin contact; highly toxic by all routes of exposure
ISOLATION: ERG 151: isolate spill 25m all directions; protective action distance 100m downwind during spill; if fire involves large quantities, 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 2781 — Bipyridilium pesticide, solid, poisonous
Class: 6 | Placard: Toxic | ERG Guide: 151
Appearance: Typically appears as white to tan or yellowish crystalline solid or granular powder. Odorless or slight characteristic odor. Solid at room temperature.
Water Reactivity: Soluble in water; no significant reaction with water
Extinguishing: Use dry chemical, CO2, water spray, or foam for surrounding fires
PPE: Level A or B required; full chemical protective suit, SCBA mandatory; avoid all skin contact; highly toxic by all routes of exposure
Isolation: ERG 151: isolate spill 25m all directions; protective action distance 100m downwind during spill; if fire involves large quantities, 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/2781 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2781 Bipyridilium pesticide, solid, poisonous Cls6 ERG151 | allfirefighter.com/hazmat/un/2781SMS / 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/2781
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Frequently Asked Questions about UN 2781
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 or B required; full chemical protective suit, SCBA mandatory; avoid all skin contact; highly toxic by all routes of exposure
Water reactivity: Soluble in water; no significant reaction with water. Recommended extinguishing: Use dry chemical, CO2, water spray, or foam for surrounding fires.
ERG Guide 151 recommendation: ERG 151: isolate spill 25m all directions; protective action distance 100m downwind during spill; if fire involves large quantities, 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.