☣️ UN 1627 • CLASS 6
UN 1627 — Mercurous nitrate
Placard: Toxic. ERG Guide 141. 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.
Mercurous nitrate is a toxic substance that can accelerate burning when involved in a fire. It may also explode from heat or contamination.
Hazard overview: These substances will accelerate burning when involved in a fire. May explode from heat or contamination.
Response guidance: Use water spray to control fire, CO2, dry chemical. Avoid organic materials which may react with oxidizer.
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UN 1627 Quick Details
UN 1627
Product name: Mercurous nitrate
DOT Class: 6
Placard type: Toxic
ERG Guide: 141 (check current ERG)
Initial isolation: ERG 141: isolate spill area immediate 25m in all directions; for large spill increase initial isolation to 50m; if tank/railcar involved in fire isolate 800m in all directions
Common Hazards of UN 1627
- These substances will accelerate burning when involved in a fire.
- May explode from heat or contamination.
- Some may burn rapidly.
- Some will react explosively with hydrocarbons (fuels).
- May ignite combustibles (wood, paper, oil, clothing, etc.).
- Containers may explode when heated.
- Runoff may create fire or explosion hazard.
- Toxic by ingestion.
Chemical Identity & Physical Properties
White to grayish-white crystalline solid or powder. Odorless. Decomposes upon exposure to light, turning gray or black.
| Also known as | Mercury(I) nitrateMercurous nitrate dihydrateNitric acid mercury(I) saltMercuric nitrate |
| CAS Number | 10415-75-5 |
| Appearance | White to grayish-white crystalline solid or powder. Odorless. Decomposes upon exposure to light, turning gray or black. |
| Flash Point | Not applicable (non-combustible oxidizing solid) |
| Boiling Point | Not applicable (decomposes before boiling at approximately 70C) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Soluble in water with slow decomposition; no violent reaction but may form acidic solution |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1627
Extinguishing Media
Water spray to control fire, CO2, dry chemical; avoid organic materials which may react with oxidizer
PPE Requirements
⚠️ Level B minimum with full face respirator; mercury compound requires impervious protective clothing and SCBA for fire or spill response
Level B minimum with full face respirator; mercury compound requires impervious protective clothing and SCBA for fire or spill response
Isolation & Evacuation
ERG 141: isolate spill area immediate 25m in all directions; for large spill increase initial isolation to 50m; if tank/railcar involved in fire isolate 800m in all directions
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 141).
First Actions for a UN 1627 Incident
- 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
- Consider initial downwind evacuation for at least 100 meters (330 feet).
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📋 Copy & Share Field Card
UN 1627 — Mercurous nitrateHAZMAT RADIO NOTE — UN 1627
Product: Mercurous nitrate
Class 6 / Toxic / ERG 141
PPE: Level B minimum with full face respirator; mercury compound requires impervious protective clothing and SCBA for fire or spill response
ISOLATION: ERG 141: isolate spill area immediate 25m in all directions; for large spill increase initial isolation to 50m; if tank/railcar involved in fire isolate 800m in 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 1627 — Mercurous nitrate
Class: 6 | Placard: Toxic | ERG Guide: 141
Appearance: White to grayish-white crystalline solid or powder. Odorless. Decomposes upon exposure to light, turning gray or black.
Water Reactivity: Soluble in water with slow decomposition; no violent reaction but may form acidic solution
Extinguishing: Water spray to control fire, CO2, dry chemical; avoid organic materials which may react with oxidizer
PPE: Level B minimum with full face respirator; mercury compound requires impervious protective clothing and SCBA for fire or spill response
Isolation: ERG 141: isolate spill area immediate 25m in all directions; for large spill increase initial isolation to 50m; if tank/railcar involved in fire isolate 800m in all directions
— Key Hazards —
• These substances will accelerate burning when involved in a fire.
• May explode from heat or contamination.
• Some may burn rapidly.
— First Actions —
• 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
SOURCE: allfirefighter.com/hazmat/un/1627 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN1627 Mercurous nitrate Cls6 ERG141 | ERG 141: isolate spill area immediate 25m in all directions; for large spill inc | allfirefighter.com/hazmat/un/1627SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/mercurous-nitrate-un-1627
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Frequently Asked Questions about UN 1627
No
Accelerates burning when involved in a fire, May explode from heat or contamination
Use water spray to control fire, CO2, dry chemical
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.