UN 1198 — Formalin (flammable)
Placard: Flammable. ERG Guide 132. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1198 is Formalin (flammable), a formaldehyde solution assigned to ERG Guide 132. It combines flammable solvent behavior with severe irritant and toxic formaldehyde vapor hazards.
Hazard overview: UN 1198 presents flammable liquid, formaldehyde vapor and irritant/carcinogen exposure hazards. Vapors can injure eyes and respiratory tissue, and fire may produce toxic gases.
Response guidance: For a UN 1198 incident, responders should confirm the product using shipping papers, container markings, SDS and ERG Guide 132. Establish incident command, isolate the area, stay upwind and uphill, remove ignition sources when safe, keep vapors or runoff out of sewers and use compatible fire-control agents from a protected position.
Firefighter training notes: Training for UN 1198 should emphasize combined toxicity, skin absorption, flammable vapor behavior, air monitoring and decontamination. Common errors include treating the incident only as a fire, entering vapor areas without SCBA, allowing sewer entry and failing to control ignition sources. Use ERG 132, SDS and incident command.
Regulatory context: Formalin (flammable) is regulated as a hazardous material and may have additional occupational exposure, environmental and waste controls because of toxicity as well as flammability. Verify current requirements through shipping papers, SDS, facility documents and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Formalin (flammable) should be stored in tightly closed compatible containers in a cool, dry, well-ventilated flammable-liquid area with exposure controls, secondary containment and drain protection. Keep away from heat, ignition sources, oxidizers and incompatible materials.
UN 1198 Quick Details
Common Hazards of UN 1198
- FLAMMABLE and TOXIC/IRRITATING; formaldehyde vapor may cause severe eye, skin and respiratory irritation.
- Vapors may form explosive mixtures with air and travel to an ignition source.
- Liquid and vapor may irritate or burn skin, eyes and respiratory tissue.
- Vapors are heavier than air and may collect in low, confined or sewer areas.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or spill control may cause environmental contamination.
- Containers may rupture or explode when heated.
- Formaldehyde is a recognized carcinogen; minimize inhalation and skin contact.
Chemical Identity & Physical Properties
Clear, colorless aqueous solution (typically 37-50% formaldehyde) with a pungent, irritating odor. Liquid at room temperature.
| Also known as | Formaldehyde solutionFormalinMethylene oxide solutionFormic aldehyde aqueousFormol |
| CAS Number | 50-00-0 |
| Appearance | Clear, colorless aqueous solution (typically 37-50% formaldehyde) with a pungent, irritating odor. Liquid at room temperature. |
| Flash Point | 50-85C (122-185F) depending on concentration |
| Boiling Point | 96-101C (205-214F) |
| Vapor Density | 1.03-1.09 (heavier than air) |
| Water Reactivity | Miscible with water; no violent reaction but dilution reduces flammability |
Fireground Response Guidance — UN 1198
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fire or confined-space exposure. Chemical-resistant gloves, boots, splash protection and protective clothing should be selected using SDS, monitoring results and incident command because inhalation and skin absorption can be serious.
Isolation & Evacuation
First Actions for a UN 1198 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.
- Eliminate ignition sources if it is safe to do so.
- Do not touch or walk through spilled liquid unless properly trained and wearing appropriate protective equipment.
- Avoid breathing vapors and avoid skin or eye contact with liquid.
- Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
- Isolate the spill or leak area for at least 50 meters (150 feet) in all directions.
- For large spills, fire involvement or strong vapor movement, expand isolation and consider downwind evacuation based on monitoring and incident command.
- Use ERG Guide 132, shipping papers, SDS and local SOP for protective actions and entry decisions.
📋 Copy & Share Field Card
UN 1198 — Formalin (flammable)Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.