☣️ UN 3413 • CLASS 6
UN 3413 — Potassium cyanide, solution
Placard: Toxic. ERG Guide 157. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ Verification required:
Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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.
UN 3413 is Potassium cyanide, solution, an extremely toxic aqueous cyanide solution. It can release hydrogen cyanide gas if acidified or heated, so responders should treat the incident as both a liquid poison and potential inhalation hazard.
Hazard overview: UN 3413 is highly toxic by ingestion, skin absorption and inhalation of vapors or hydrogen cyanide generated from the solution. Contact with acids, acidic runoff or some firefighting residues can release deadly HCN gas. Fire may produce toxic fumes and contaminated runoff.
Response guidance: For UN 3413, isolate the area, stay upwind, keep acids away and prevent entry to sewers or waterways. Do not allow unprotected personnel to contact liquid or contaminated surfaces. Use ERG 157, monitoring for HCN when available, and coordinate medical support for possible cyanide exposure.
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UN 3413 Quick Details
UN 3413
Product name: Potassium cyanide, solution
DOT Class: 6
Placard type: Toxic
ERG Guide: 157 (check current ERG)
Initial isolation: ERG 157: isolate spill area immediately 25-50m all directions; evacuate 500m downwind if tank/railcar involved; cyanide is immediately dangerous; lethal doses via skin absorption possible
Common Hazards of UN 3413
- TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
- Reaction with water or moist air may release toxic, corrosive or flammable gases.
- Reaction with water may generate much heat that will increase the concentration of fumes in the air.
- Fire will produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental
- Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive
- UN1802, UN2032, UN3084, UN3093, UN1796 (above 50%), UN1826 (above 50%), and UN2031 (above
- Vapors may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.).
Chemical Identity & Physical Properties
UN 3413 is usually a clear to slightly colored aqueous liquid. It may have a faint bitter-almond odor if hydrogen cyanide is present, but odor is unreliable because many people cannot detect it.
| Also known as | Potassium cyanide solutionKCN solutionCyanide of potassium solutionHydrocyanic acid potassium salt solution |
| CAS Number | 151-50-8 |
| Appearance | Clear to slightly colored aqueous solution with a faint bitter almond odor (not detectable by all individuals). Liquid at room temperature. |
| Flash Point | Not applicable (aqueous solution, non-flammable) |
| Boiling Point | Approximately 100°C (212°F), similar to water depending on concentration |
| Vapor Density | Not applicable (aqueous solution) |
| Water Reactivity | Miscible with water; reacts with acids to release highly toxic hydrogen cyanide gas (HCN); moisture may accelerate decomposition |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3413
Extinguishing Media
Water spray, foam, CO2, dry chemical; avoid acids which generate HCN gas
PPE Requirements
⚠️ Level A or B recommended; SCBA required; chemical-resistant suit, gloves, boots; extreme toxicity via all routes of exposure
Use positive-pressure SCBA and chemical-resistant clothing with gloves and boots resistant to cyanide solutions. Level A or B protection is appropriate depending on vapor risk, spill size and monitoring results; avoid all skin contact.
Isolation & Evacuation
ERG 157: isolate spill area immediately 25-50m all directions; evacuate 500m downwind if tank/railcar involved; cyanide is immediately dangerous; lethal doses via skin absorption possible
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 157).
First Actions for a UN 3413 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
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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UN 3413 — Potassium cyanide, solutionHAZMAT RADIO NOTE — UN 3413
Product: Potassium cyanide, solution
Class 6 / Toxic / ERG 157
PPE: Level A or B recommended; SCBA required; chemical-resistant suit, gloves, boots; extreme toxicity via all routes of exposure
ISOLATION: ERG 157: isolate spill area immediately 25-50m all directions; evacuate 500m downwind if tank/railcar involved; cyanide is immediately dangerous; lethal doses via skin absorption possible
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 3413 — Potassium cyanide, solution
Class: 6 | Placard: Toxic | ERG Guide: 157
Appearance: Clear to slightly colored aqueous solution with a faint bitter almond odor (not detectable by all individuals). Liquid at room temperature.
Water Reactivity: Miscible with water; reacts with acids to release highly toxic hydrogen cyanide gas (HCN); moisture may accelerate decomposition
Extinguishing: Water spray, foam, CO2, dry chemical; avoid acids which generate HCN gas
PPE: Level A or B recommended; SCBA required; chemical-resistant suit, gloves, boots; extreme toxicity via all routes of exposure
Isolation: ERG 157: isolate spill area immediately 25-50m all directions; evacuate 500m downwind if tank/railcar involved; cyanide is immediately dangerous; lethal doses via skin absorption possible
— Key Hazards —
• TOXIC and/or CORROSIVE; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance
• Reaction with water or moist air may release toxic, corrosive or flammable gases.
• Reaction with water may generate much heat that will increase the concentration of fumes in the air.
— 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/potassium-cyanide-solution-un-3413 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3413 Potassium cyanide, solution Cls6 ERG157 | allfirefighter.com/hazmat/un/potassium-cyanide-solution-un-3413SMS / 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/potassium-cyanide-solution-un-3413
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Frequently Asked Questions about UN 3413
UN 3413 is Potassium cyanide, solution. It should be identified from shipping papers, markings and the SDS before responders work near the release.
ERG Guide 157 applies to UN 3413 for initial isolation, protective actions and first-response guidance.
UN 3413 is not primarily classified as flammable, but fire may produce toxic or corrosive gases and containers may become dangerous when heated.
Use positive-pressure SCBA and chemical-resistant clothing with gloves and boots resistant to cyanide solutions. Level A or B protection is appropriate depending on vapor risk, spill size and monitoring results; avoid all skin contact.
UN 3413 is highly toxic by ingestion, skin absorption and inhalation of vapors or hydrogen cyanide generated from the solution.
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.