☣️ UN 2186 • CLASS 2

Hydrogen chloride, refrigerated liquid

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

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⚠️ 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 2186
Class: 2
Placard type: Toxic Gas
ERG: Guide 125 (check current ERG)
Isolation: ERG 125: isolate 150m all directions initially; for large spills isolate 800m downwind; evacuate immediate area if tank rupture
Chemical & Response Details
Also known asHydrochloric acid gasMuriatic acid gasAnhydrous hydrogen chlorideHCl
CAS Number7647-01-0
AppearanceColorless to slightly yellow liquefied compressed gas with a pungent, irritating odor. Fumes strongly in moist air.
Flash PointNot applicable (non-flammable gas)
Boiling Point-85C (-121F)
Vapor Density1.3 (heavier than air)
Water ReactivityReacts violently with water generating heat and corrosive hydrochloric acid solution; causes violent fuming
ExtinguishingDo not use water directly on liquid; use water spray from distance to absorb vapors; dry chemical for small fires
PPE⚠️ Level A or B required; full-face SCBA; chemical-resistant suit with thermal protection for cryogenic exposure; avoid all contact
IsolationERG 125: isolate 150m all directions initially; for large spills isolate 800m downwind; evacuate immediate area if tank rupture
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • TOXIC and/or CORROSIVE; may be fatal if inhaled, ingested or absorbed through skin.
  • Vapors are extremely irritating and corrosive.
  • Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
  • Fire will produce irritating, corrosive and/or toxic gases.
  • Runoff from fire control or dilution water may cause environmental contamination.
  • Some may burn but none ignite readily.
  • Vapors from liquefied gas are initially heavier than air and spread along ground.
  • Some of these materials may react violently with water.
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.
  • Many gases are heavier than air and will spread along the ground and collect in low or confined areas
  • Ventilate closed spaces before entering, but only if properly trained and equipped.
  • Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
  • 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 2186 — Hydrogen chloride, refrigerated liquid
HAZMAT RADIO NOTE — UN 2186 Product: Hydrogen chloride, refrigerated liquid Class 2 / Toxic Gas / ERG 125 PPE: Level A or B required; full-face SCBA; chemical-resistant suit with thermal protection for cryogenic exposure; avoid all contact ISOLATION: ERG 125: isolate 150m all directions initially; for large spills isolate 800m downwind; evacuate immediate area if tank rupture 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 2186 — Hydrogen chloride, refrigerated liquid Class: 2 | Placard: Toxic Gas | ERG Guide: 125 Appearance: Colorless to slightly yellow liquefied compressed gas with a pungent, irritating odor. Fumes strongly in moist air. Water Reactivity: Reacts violently with water generating heat and corrosive hydrochloric acid solution; causes violent fuming Extinguishing: Do not use water directly on liquid; use water spray from distance to absorb vapors; dry chemical for small fires PPE: Level A or B required; full-face SCBA; chemical-resistant suit with thermal protection for cryogenic exposure; avoid all contact Isolation: ERG 125: isolate 150m all directions initially; for large spills isolate 800m downwind; evacuate immediate area if tank rupture — Key Hazards — • TOXIC and/or CORROSIVE; may be fatal if inhaled, ingested or absorbed through skin. • Vapors are extremely irritating and corrosive. • Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. — 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. • Many gases are heavier than air and will spread along the ground and collect in low or confined areas SOURCE: allfirefighter.com/hazmat/un/2186 | 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)
UN2186 Hydrogen chloride, refrigerated liquid Cls2 ERG125 | allfirefighter.com/hazmat/un/2186SMS / 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/2186
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; may be fatal if inhaled, ingested or absorbed through skin. Vapors are extremely irritating and corrosive. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause environmental contamination. Some may burn but none ignite readily. Vapors from liquefied gas are initially heavier than air and spread along ground. Some of these materials may react violently with water.

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 or B required; full-face SCBA; chemical-resistant suit with thermal protection for cryogenic exposure; avoid all contact

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 125 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.