☣️ UN 1802 • CLASS 8

UN 1802 — Perchloric acid, with not more than 50% acid

Placard: Corrosive. ERG Guide 157. 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.

UN 1802 is Perchloric acid, with not more than 50% acid, a Class 8 corrosive oxidizing acid assigned to ERG Guide 157. It is less concentrated than higher-strength perchloric acid but still requires strict separation from organics and combustibles.

Hazard overview: UN 1802 presents corrosive burn, oxidizer, heat-on-dilution and reactive-residue hazards. Contamination with organic material, reducing agents or combustible absorbents can create dangerous reaction conditions.

Response guidance: For a UN 1802 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 incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.

Firefighter training notes: Training for UN 1802 should emphasize oxidizing acid behavior, incompatibility with organics/combustibles, residue drying hazards, fume control and runoff containment. Use ERG 157, SDS and local SOP.

Regulatory context: Perchloric acid, with not more than 50% acid is regulated as a hazardous material for transportation and emergency response purposes. Transportation, workplace exposure, spill reporting, waste handling, storage and environmental requirements may vary by concentration, formulation, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.

Storage & handling: Perchloric acid, with not more than 50% acid should be stored in compatible corrosion-resistant containers in a clean, cool, well-ventilated oxidizing-acid area away from organics, combustibles, reducing agents, metals where incompatible, heat and contamination. Avoid absorbents or residues that could dry and concentrate.

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UN 1802 Quick Details

UN 1802
Product name: Perchloric acid, with not more than 50% acid
DOT Class: 8
Placard type: Corrosive
ERG Guide: 157 (check current ERG)
Initial isolation: ERG 157: isolate spill 25-50m; evacuate 300m downwind if large spill; avoid contact with organics

Common Hazards of UN 1802

  • CORROSIVE oxidizing acid solution; inhalation, ingestion or skin/eye contact may cause severe injury.
  • Even at not more than 50% acid, contamination with organics, combustibles or reducing agents may create dangerous reaction hazards.
  • Dilution with water may generate heat and increase fuming.
  • Heating, drying or concentration of residues may increase oxidizing/reactive hazards.
  • Fire may produce irritating, corrosive and/or toxic gases.
  • Runoff may be corrosive, oxidizing and environmentally hazardous.
  • Containers may rupture or fail when heated.

Chemical Identity & Physical Properties

Colorless to pale yellow aqueous solution with a pungent, irritating odor. Fuming liquid at higher concentrations. Highly corrosive and oxidizing.

Also known asPerchloric acid solutionPerchloric acid aqueousHydrogen perchloratePerchloric acid ≤50%
CAS Number7601-90-3
AppearanceColorless to pale yellow aqueous solution with a pungent, irritating odor. Fuming liquid at higher concentrations. Highly corrosive and oxidizing.
Flash PointNot applicable (non-flammable aqueous solution, though oxidizer)
Boiling Point203C (397F) at 72% concentration; lower concentrations boil closer to water
Vapor DensityNot applicable (aqueous solution)
Water ReactivityGenerates heat when diluted; concentrated acid reacts violently with organics and combustibles
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 1802

Extinguishing Media

Use water spray from a protected position when appropriate for dilution/cooling, but keep organics, combustibles and incompatible absorbents away. Contain runoff as corrosive oxidizer contamination.

PPE Requirements

⚠️ Level B minimum; SCBA, full face shield, acid-resistant suit, neoprene/butyl gloves required

Use positive-pressure SCBA for vapor, mist, dust, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing selected from SDS for corrosive contact.

Isolation & Evacuation

ERG 157: isolate spill 25-50m; evacuate 300m downwind if large spill; avoid contact with organics
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 157).

First Actions for a UN 1802 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, mist or spray and avoid skin or eye contact.
  • Keep organic materials, combustibles, reducing agents and contaminated absorbents away from the acid.
  • Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
  • 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, water reaction or unknown concentration is present.
  • Use ERG Guide 157, shipping papers, SDS, air monitoring and incident command for protective actions.
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📋 Copy & Share Field Card

UN 1802 — Perchloric acid, with not more than 50%
HAZMAT RADIO NOTE — UN 1802 Product: Perchloric acid, with not more than 50% acid Class 8 / Corrosive / ERG 157 PPE: Level B minimum; SCBA, full face shield, acid-resistant suit, neoprene/butyl gloves required ISOLATION: ERG 157: isolate spill 25-50m; evacuate 300m downwind if large spill; avoid contact with organics 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 1802 — Perchloric acid, with not more than 50% acid Class: 8 | Placard: Corrosive | ERG Guide: 157 Appearance: Colorless to pale yellow aqueous solution with a pungent, irritating odor. Fuming liquid at higher concentrations. Highly corrosive and oxidizing. Water Reactivity: Generates heat when diluted; concentrated acid reacts violently with organics and combustibles Extinguishing: Use water spray from a protected position when appropriate for dilution/cooling, but keep organics, combustibles and incompatible absorbents away. Contain runoff as corrosive oxidizer contamination. PPE: Level B minimum; SCBA, full face shield, acid-resistant suit, neoprene/butyl gloves required Isolation: ERG 157: isolate spill 25-50m; evacuate 300m downwind if large spill; avoid contact with organics — Key Hazards — • CORROSIVE oxidizing acid solution; inhalation, ingestion or skin/eye contact may cause severe injury. • Even at not more than 50% acid, contamination with organics, combustibles or reducing agents may create dangerous reaction hazards. • Dilution with water may generate heat and increase fuming. — First Actions — • 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, mist or spray and avoid skin or eye contact. SOURCE: allfirefighter.com/hazmat/un/perchloric-acid-with-not-un-1802 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN1802 Perchloric acid, with not more than 50% acid Cls8 ERG157 | allfirefighter.com/hazmat/un/perchloric-acid-with-not-un-1802SMS / 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/perchloric-acid-with-not-un-1802

Related UN Numbers in Class 8

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 1802

UN 1802 is Perchloric acid, with not more than 50% acid, a hazardous material assigned to ERG Guide 157.

No. It is not flammable, but it can promote or intensify reactions with combustibles and organic contamination.

ERG Guide 157 applies to UN 1802 for initial isolation, protective actions and first response guidance.

UN 1802 presents corrosive burn, oxidizer, heat-on-dilution and reactive-residue hazards. Contamination with organic material, reducing agents or combustible absorbents can create dangerous reaction conditions.

Use positive-pressure SCBA for vapor, mist, dust, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing selected from SDS for corrosive contact.

Perchloric acid is an oxidizing acid; contamination with organic materials, combustibles or reducing agents can create dangerous reaction or fire conditions.
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.