UN 1627 — Mercurous nitrate
Placard: Toxic. ERG Guide 141. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1627 is Mercurous nitrate, a toxic mercury nitrate oxidizer assigned to ERG Guide 141. It can intensify fire and create toxic mercury-contaminated dust, smoke or runoff.
Hazard overview: UN 1627 presents oxidizer, mercury toxicity and contamination hazards. Keep fuels, organics and reducing agents away, control dust and contain runoff as toxic oxidizer waste.
Response guidance: For a UN 1627 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 141. Establish incident command, isolate the area, stay upwind, prevent dust or vapor exposure, control runoff and choose entry or cleanup actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1627 should emphasize oxidizer fire acceleration, mercury contamination, dust control, incompatible fuels/organics, runoff containment and decontamination. Use ERG 141, SDS and local SOP.
Regulatory context: Mercurous nitrate is regulated as a toxic mercury hazardous material. Transportation, occupational exposure, spill reporting, waste handling, storage and environmental controls may vary by compound, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Mercurous nitrate should be stored in compatible oxidizer/toxic storage away from fuels, organic materials, reducing agents, heat and contamination. Keep containers closed, dry and clearly labeled, and plan for mercury-contaminated runoff or waste.
UN 1627 Quick Details
Common Hazards of UN 1627
- TOXIC mercury oxidizer; may intensify fire and accelerate burning of combustible materials.
- May react dangerously with fuels, organic materials, reducing agents or contamination.
- Heating or confinement may cause decomposition and pressure buildup.
- Fire may produce toxic mercury fumes, nitrogen oxides and irritating gases.
- Runoff may spread toxic mercury contamination and oxidizing material.
- Containers may rupture or explode when heated.
- Dust or solution contact may injure eyes, skin and respiratory tissue.
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 |
Fireground Response Guidance — UN 1627
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for fire, dust, decomposition or confined-space exposure. Chemical-resistant gloves, eye/face protection and protective clothing should be selected from SDS; avoid mercury-contaminated dust, solution and runoff.
Isolation & Evacuation
First Actions for a UN 1627 Incident
- CALL 911. Then call the emergency response telephone number on the shipping paper, if available.
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Avoid breathing vapors, fumes, dust or mist and avoid all skin or eye contact.
- Keep fuels, organics, reducing agents and contaminated absorbents away from the material.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Avoid creating dust clouds or spreading contaminated powder, solution, runoff or debris.
- Ventilate closed spaces before entering, but only if properly trained, equipped, monitored and authorized by incident command.
- Isolate the spill or leak area and expand the perimeter if dust, vapor, fire involvement or unknown concentration is present.
- Use ERG Guide 141, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1627 — Mercurous nitrateUse for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.