UN 3251 — Isosorbide-5-mononitrate
Placard: Flammable Solid. ERG Guide 133. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3251 Isosorbide-5-mononitrate is assigned to ERG Guide 133 for initial emergency response. White to off-white crystalline powder or granules, odorless to slight characteristic odor, solid at room temperature. Verify the exact product from shipping papers and SDS before selecting tactics.
Hazard overview: Primary hazards: a flammable solid that may ignite by heat, sparks, friction or moisture. Flammable/combustible material. May be ignited by friction, heat, sparks or flames.
Response guidance: For a UN 3251 incident, isolate the area, keep unauthorized personnel away, stay upwind/uphill and confirm the exact material from shipping papers and SDS. Use compatible extinguishing media and prevent contaminated runoff from entering waterways. Follow ERG Guide 133 and local incident command procedures.
UN 3251 Quick Details
Common Hazards of UN 3251
- Flammable/combustible material.
- May be ignited by friction, heat, sparks or flames.
- Some may burn rapidly with flare-burning effect.
- Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence.
- Substance may be transported in a molten form at a temperature that may be above its flash point.
- May re-ignite after fire is extinguished.
- Fire may produce irritating and/or toxic gases.
- Contact may cause burns to skin and eyes.
Chemical Identity & Physical Properties
White to off-white crystalline powder or granules, odorless to slight characteristic odor, solid at room temperature.
| Also known as | ISMNIsosorbide mononitrate5-ISMNImdurMonoketIsmo |
| CAS Number | 16051-77-7 |
| Appearance | White to off-white crystalline powder or granules, odorless to slight characteristic odor, solid at room temperature. |
| Flash Point | Not applicable (combustible solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | No significant reaction with water, slightly soluble |
Fireground Response Guidance — UN 3251
Extinguishing Media
PPE Requirements
Level C minimum; full protective clothing, SCBA if involved in fire or heated decomposition
Isolation & Evacuation
First Actions for a UN 3251 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.
- Isolate spill or leak area for at least 25 meters (75 feet) in all directions.
- Consider initial downwind evacuation for at least 100 meters (330 feet).
📋 Copy & Share Field Card
UN 3251 — Isosorbide-5-mononitrateUse 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.