UN 1451 — Caesium nitrate
Placard: Oxidizer. ERG Guide 140. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1451 is Caesium nitrate, a Class 5 oxidizer assigned to ERG Guide 140. It is not a normal fuel, but it can intensify fires and react dangerously with combustibles, fuels or contamination.
Hazard overview: UN 1451 presents oxidizer, contamination and container-heating hazards. It can accelerate burning, may decompose or react violently when heated or contaminated, and runoff may spread oxidizing material.
Response guidance: For a UN 1451 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 140. Establish incident command, isolate the area, stay upwind, prevent incompatible contact and choose extinguishing or spill-control actions based on the ERG, SDS and local SOP.
Firefighter training notes: Training for UN 1451 should emphasize oxidizer fire behavior, separation from fuels and organics, contamination control, dust avoidance, container-heating hazards and correct extinguishing decisions. Common errors include treating oxidizers like ordinary combustibles, mixing contaminated material and using incompatible cleanup methods. Use ERG 140, SDS and local SOP.
Regulatory context: Caesium nitrate is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by formulation, 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: Caesium nitrate should be stored in compatible oxidizer storage away from fuels, organic materials, reducing agents, acids where incompatible, heat, ignition sources and contamination. Keep containers closed, dry, clearly labeled and separated from combustible packaging or spilled residues.
UN 1451 Quick Details
Common Hazards of UN 1451
- OXIDIZER: may intensify fire and accelerate burning of combustible materials.
- May ignite combustibles such as wood, paper, oil, clothing or packaging.
- May react dangerously with fuels, organic materials, reducing agents or contamination.
- Containers may rupture or explode when heated.
- Fire may produce irritating and/or toxic gases.
- Runoff may create fire, explosion or environmental hazards.
- Dust, solution or decomposition products may irritate or injure eyes, skin or respiratory tissue.
Chemical Identity & Physical Properties
White or colorless crystalline solid, odorless. Hygroscopic powder or crystals at room temperature.
| Also known as | Cesium nitrateNitric acid cesium saltCesium(I) nitrateCaesium mononitrate |
| CAS Number | 7789-18-6 |
| Appearance | White or colorless crystalline solid, odorless. Hygroscopic powder or crystals at room temperature. |
| Flash Point | Not applicable (oxidizing solid, non-flammable but supports combustion) |
| Boiling Point | Decomposes at 414C (777F) before boiling |
| Vapor Density | Not applicable (solid with negligible vapor pressure) |
| Water Reactivity | Soluble in water without hazardous reaction, but solution may be corrosive |
Fireground Response Guidance — UN 1451
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 and incident command.
Isolation & Evacuation
First Actions for a UN 1451 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.
- Keep combustibles, fuels, organics, reducing agents and contaminated materials away from the spill.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Avoid creating dust clouds and prevent runoff from contacting combustibles or drains when possible.
- Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
- Isolate the spill or fire area and expand the perimeter if large quantities, contamination, heating or container involvement are present.
- Use ERG Guide 140, shipping papers, SDS and local SOP for protective actions and entry decisions.
📋 Copy & Share Field Card
UN 1451 — Caesium 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.