☣️ UN 2209 • CLASS 8

Formaldehyde, solution (corrosive)

Placard: Corrosive. 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 2209
Class: 8
Placard type: Corrosive
ERG: Guide 153 (check current ERG)
Isolation: ERG 153: isolate spill/leak area 50m in all directions; for large spills isolate 150m and evacuate downwind 300m; avoid contact and inhalation
Chemical & Response Details
Also known asFormalinMethanalMethyl aldehydeMethylene oxideFormic aldehydeOxomethane
CAS Number50-00-0
AppearanceClear, colorless to slightly cloudy aqueous solution with a pungent, irritating odor. Typically contains 37-50% formaldehyde by weight with methanol as a stabilizer.
Flash Point85C (185F) for 37% solution; varies with concentration
Boiling Point96-101C (205-214F) depending on concentration
Vapor Density1.03-1.09 (heavier than air)
Water ReactivityMiscible with water; no violent reaction but dilution generates heat
ExtinguishingAlcohol-resistant foam, CO2, dry chemical; water spray for cooling
PPE⚠️ Level B minimum with full face SCBA; chemical-resistant suit, gloves, and boots; high vapor toxicity requires respiratory protection
IsolationERG 153: isolate spill/leak area 50m in all directions; for large spills isolate 150m and evacuate downwind 300m; avoid contact and inhalation
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
  • Methyl bromoacetate (UN2643) is an eye irritant/lachrymator (causes flow of tears).
  • 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
  • Combustible material: may burn but does not ignite readily.
  • When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion
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 2209 — Formaldehyde, solution (corrosive)
HAZMAT RADIO NOTE — UN 2209 Product: Formaldehyde, solution (corrosive) Class 8 / Corrosive / ERG 153 PPE: Level B minimum with full face SCBA; chemical-resistant suit, gloves, and boots; high vapor toxicity requires respiratory protection ISOLATION: ERG 153: isolate spill/leak area 50m in all directions; for large spills isolate 150m and evacuate downwind 300m; avoid contact and inhalation 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 2209 — Formaldehyde, solution (corrosive) Class: 8 | Placard: Corrosive | ERG Guide: 153 Appearance: Clear, colorless to slightly cloudy aqueous solution with a pungent, irritating odor. Typically contains 37-50% formaldehyde by weight with methanol as a stabilizer. Water Reactivity: Miscible with water; no violent reaction but dilution generates heat Extinguishing: Alcohol-resistant foam, CO2, dry chemical; water spray for cooling PPE: Level B minimum with full face SCBA; chemical-resistant suit, gloves, and boots; high vapor toxicity requires respiratory protection Isolation: ERG 153: isolate spill/leak area 50m in all directions; for large spills isolate 150m and evacuate downwind 300m; avoid contact and inhalation — Key Hazards — • TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury • Methyl bromoacetate (UN2643) is an eye irritant/lachrymator (causes flow of tears). • Contact with molten substance may cause severe burns to skin and eyes. — 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/2209 | 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)
UN2209 Formaldehyde, solution (corrosive) Cls8 ERG153 | allfirefighter.com/hazmat/un/2209SMS / 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/2209
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 Methyl bromoacetate (UN2643) is an eye irritant/lachrymator (causes flow of tears). 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 Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion

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 with full face SCBA; chemical-resistant suit, gloves, and boots; high vapor toxicity requires respiratory protection

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 153 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.