☣️ UN 1613 • CLASS 6

Hydrocyanic acid, aqueous solution, with not more than 20% hydrogen cyanide

Placard: Toxic. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.

🚒☣️
⚠️ 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.
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Quick details
UN 1613
Class: 6
Placard type: Toxic
ERG: Guide 154 (check current ERG)
Isolation: ERG 154: isolate spill 25-50m all directions; evacuate immediate area; large spill: isolate 100m+ and consider evacuation 300m+ downwind
Chemical & Response Details
Also known asHydrogen cyanide solutionHydrocyanic acid solutionPrussic acid aqueousHCN solutionCyanide solution
CAS Number74-90-8
AppearanceClear to pale yellow liquid with a faint bitter almond odor (though not everyone can detect this). Highly toxic aqueous solution at room temperature.
Flash Point-18C (0F)
Boiling Point26C (79F) for pure HCN; solution boiling point varies with concentration
Vapor Density0.9 (lighter than air for vapor)
Water ReactivityAlready dissolved in water; solution is stable but highly toxic vapors may evolve
ExtinguishingWater spray to reduce vapors, CO2, dry chemical; alcohol-resistant foam may be used
PPE⚠️ Level A required; full-face SCBA mandatory; butyl rubber or Viton gloves; no skin contact whatsoever; cyanide antidote kit on standby
IsolationERG 154: isolate spill 25-50m all directions; evacuate immediate area; large spill: isolate 100m+ and consider evacuation 300m+ downwind
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury
  • Contact with molten substance may cause severe burns to skin and eyes.
  • Avoid any skin contact.
  • Fire may 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
  • Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.).
  • Corrosives in contact with metals may evolve flammable hydrogen gas.
First actions (field-minded)
  • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
  • 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 1613 — Hydrocyanic acid, aqueous solution, with
HAZMAT RADIO NOTE — UN 1613 Product: Hydrocyanic acid, aqueous solution, with not more than 20% hydrogen cyanide Class 6 / Toxic / ERG 154 PPE: Level A required; full-face SCBA mandatory; butyl rubber or Viton gloves; no skin contact whatsoever; cyanide antidote kit on standby ISOLATION: ERG 154: isolate spill 25-50m all directions; evacuate immediate area; large spill: isolate 100m+ and consider evacuation 300m+ downwind ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 1613 — Hydrocyanic acid, aqueous solution, with not more than 20% hydrogen cyanide Class: 6 | Placard: Toxic | ERG Guide: 154 Appearance: Clear to pale yellow liquid with a faint bitter almond odor (though not everyone can detect this). Highly toxic aqueous solution at room temperature. Water Reactivity: Already dissolved in water; solution is stable but highly toxic vapors may evolve Extinguishing: Water spray to reduce vapors, CO2, dry chemical; alcohol-resistant foam may be used PPE: Level A required; full-face SCBA mandatory; butyl rubber or Viton gloves; no skin contact whatsoever; cyanide antidote kit on standby Isolation: ERG 154: isolate spill 25-50m all directions; evacuate immediate area; large spill: isolate 100m+ and consider evacuation 300m+ downwind — Key Hazards — • TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury • Contact with molten substance may cause severe burns to skin and eyes. • Avoid any skin contact. — First Actions — • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper • Keep unauthorized personnel away. • Stay upwind, uphill and/or upstream. • Ventilate closed spaces before entering, but only if properly trained and equipped. SOURCE: allfirefighter.com/hazmat/un/1613 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN1613 Hydrocyanic acid, aqueous solution, with not more than 20% hydrogen cyanide Cls6 ERG154 | allfirefighter.com/hazmat/un/1613SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/1613
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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FAQ

TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may 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 Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas.

CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.

Level A required; full-face SCBA mandatory; butyl rubber or Viton gloves; no skin contact whatsoever; cyanide antidote kit on standby

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 154 and your department SOP/SOG for incident-specific protective actions.
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.