☣️ UN 1198 • CLASS 3

Formalin (flammable)

Placard: Flammable. 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 1198
Class: 3
Placard type: Flammable
ERG: Guide 132 (check current ERG)
Isolation: ERG 132: isolate spill 50m all directions; evacuate 800m downwind if large spill or fire
Chemical & Response Details
Also known asFormaldehyde solutionFormalinMethylene oxide solutionFormic aldehyde aqueousFormol
CAS Number50-00-0
AppearanceClear, colorless aqueous solution (typically 37-50% formaldehyde) with a pungent, irritating odor. Liquid at room temperature.
Flash Point50-85C (122-185F) depending on concentration
Boiling Point96-101C (205-214F)
Vapor Density1.03-1.09 (heavier than air)
Water ReactivityMiscible with water; no violent reaction but dilution reduces flammability
ExtinguishingAlcohol-resistant foam, CO2, dry chemical; water spray for cooling
PPE⚠️ Level B minimum; SCBA required; chemical-resistant gloves and suit due to severe irritant/carcinogen
IsolationERG 132: isolate spill 50m all directions; evacuate 800m downwind if large spill or fire
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • Flammable/combustible material.
  • May be ignited by heat, sparks or flames.
  • Vapors may form explosive mixtures with air.
  • Vapors may travel to source of ignition and flash back.
  • Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas
  • Vapor explosion hazard indoors, outdoors or in sewers.
  • Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.
  • Runoff to sewer may create fire or explosion hazard.
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 for at least 50 meters (150 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 1198 — Formalin (flammable)
HAZMAT RADIO NOTE — UN 1198 Product: Formalin (flammable) Class 3 / Flammable / ERG 132 PPE: Level B minimum; SCBA required; chemical-resistant gloves and suit due to severe irritant/carcinogen ISOLATION: ERG 132: isolate spill 50m all directions; evacuate 800m downwind if large spill or fire 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 1198 — Formalin (flammable) Class: 3 | Placard: Flammable | ERG Guide: 132 Appearance: Clear, colorless aqueous solution (typically 37-50% formaldehyde) with a pungent, irritating odor. Liquid at room temperature. Water Reactivity: Miscible with water; no violent reaction but dilution reduces flammability Extinguishing: Alcohol-resistant foam, CO2, dry chemical; water spray for cooling PPE: Level B minimum; SCBA required; chemical-resistant gloves and suit due to severe irritant/carcinogen Isolation: ERG 132: isolate spill 50m all directions; evacuate 800m downwind if large spill or fire — Key Hazards — • Flammable/combustible material. • May be ignited by heat, sparks or flames. • Vapors may form explosive mixtures with air. — 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/1198 | 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)
UN1198 Formalin (flammable) Cls3 ERG132 | ERG 132: isolate spill 50m all directions; evacuate 800m downwind if large spill | allfirefighter.com/hazmat/un/1198SMS / 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/1198
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

Flammable/combustible material. May be ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard.

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 B minimum; SCBA required; chemical-resistant gloves and suit due to severe irritant/carcinogen

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 132 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.