UN 1575 — Calcium cyanide
Placard: Toxic. ERG Guide 157. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1575 is Calcium cyanide, a highly toxic cyanide material assigned to ERG Guide 157. Water, moisture, acids or heat can release hydrogen cyanide, so air monitoring and runoff control are critical.
Hazard overview: UN 1575 presents cyanide poisoning, hydrogen cyanide gas and contaminated-runoff hazards. Avoid acid or water contact with product unless incident command confirms a safe control method, and do not rely on odor as a warning.
Response guidance: For a UN 1575 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 157. 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 1575 should emphasize hydrogen cyanide generation, acid/water incompatibility, air monitoring, SCBA use, decontamination and medical coordination. Common errors include relying on odor, using acidic cleanup materials and allowing contaminated runoff to spread. Use ERG 157, SDS and local SOP.
Regulatory context: Calcium cyanide is regulated as a toxic cyanide hazardous material and may trigger strict exposure, spill reporting, waste and emergency planning controls. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Calcium cyanide should be stored in tightly closed compatible containers in a secure, dry, well-ventilated toxic-material area away from acids, water contamination, oxidizers, heat and unauthorized access. Storage should include cyanide emergency planning and runoff control appropriate to the SDS.
UN 1575 Quick Details
Common Hazards of UN 1575
- HIGHLY TOXIC cyanide material; inhalation, ingestion or skin contact may be fatal.
- Water, moisture, acids or heat may release hydrogen cyanide gas.
- Hydrogen cyanide can be flammable and rapidly dangerous in low or poorly ventilated areas.
- Fire may produce hydrogen cyanide, nitrogen oxides and other toxic gases.
- Runoff, absorbents and contaminated equipment may carry cyanide hazards.
- Containers may rupture or fail when heated.
- Odor is not a reliable warning for hydrogen cyanide exposure.
Chemical Identity & Physical Properties
White to gray or black crystalline powder or granular solid. Odorless when dry, but may release hydrogen cyanide gas (bitter almond odor) when exposed to moisture or air.
| Also known as | CalcyanideCalcium dicyanideCyanure de calciumBlack cyanide |
| CAS Number | 592-01-8 |
| Appearance | White to gray or black crystalline powder or granular solid. Odorless when dry, but may release hydrogen cyanide gas (bitter almond odor) when exposed to moisture or air. |
| Flash Point | Not applicable (non-combustible solid, but releases flammable hydrogen cyanide gas on contact with water) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid, but hydrogen cyanide gas evolved has vapor density of 0.9) |
| Water Reactivity | Reacts with water and moisture to release highly toxic and flammable hydrogen cyanide gas. Generates heat during reaction. |
Fireground Response Guidance — UN 1575
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA and chemical protective clothing selected by hazmat specialists for cyanide dust, liquid, vapor or fire exposure. Level A may be needed for close entry or unknown hydrogen cyanide concentrations; decontamination should follow SDS and incident command.
Isolation & Evacuation
First Actions for a UN 1575 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.
- Avoid water, acids or incompatible cleanup materials contacting the product unless incident command confirms a safe control method.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Monitor for hydrogen cyanide where available; odor is not a reliable warning.
- 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 vapor, dust, fire involvement or unknown concentration is present.
- Use ERG Guide 157, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1575 — Calcium cyanideUse 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.