UN 2215 — Maleic anhydride, molten
Placard: Corrosive. ERG Guide 156. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2215 is Maleic anhydride, molten, a corrosive combustible organic anhydride assigned to ERG Guide 156. Moisture can convert it to corrosive acid while generating heat.
Hazard overview: CORROSIVE and combustible organic anhydride; inhalation of dust, vapor or mist may injure respiratory tissue. Contact can burn eyes and skin; molten material can cause severe thermal and chemical burns. Reacts with water or moisture to form corrosive organic acid and heat.
Response guidance: For a UN 2215 incident, verify the product with shipping papers, container markings, SDS and ERG Guide 156. Establish incident command, isolate the area, stay upwind, control ignition or incompatibility hazards, prevent runoff, dust or vapor spread and base entry/fire-control actions on monitoring and local SOP.
Firefighter training notes: Training for UN 2215 should emphasize corrosive vapor/dust exposure, moisture reaction, acid runoff, container heating, PPE selection and decontamination. Use ERG 156, SDS and local SOP.
Regulatory context: Maleic anhydride, molten is regulated as a hazardous material for transportation and emergency response purposes. Storage, workplace exposure, emergency planning, spill reporting, waste handling and environmental requirements vary by exact product, concentration, quantity and jurisdiction. Verify current requirements through shipping papers, SDS, container markings and applicable DOT, OSHA, EPA, NFPA, state or local authority guidance.
Storage & handling: Maleic anhydride, molten should be stored in tightly closed compatible containers in a cool, dry, ventilated area away from water/moisture, bases, oxidizers/reducing agents where incompatible, heat and unauthorized access. Provide secondary containment and prevent humid air exposure.
UN 2215 Quick Details
Common Hazards of UN 2215
- CORROSIVE and combustible organic anhydride; inhalation of dust, vapor or mist may injure respiratory tissue.
- Contact can burn eyes and skin; molten material can cause severe thermal and chemical burns.
- Reacts with water or moisture to form corrosive organic acid and heat.
- Heated vapors may form explosive mixtures with air in confined or poorly ventilated areas.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff may be acidic/corrosive and environmentally harmful.
- Containers may rupture or fail when heated or contaminated with water.
Chemical Identity & Physical Properties
White to pale yellow crystalline solid when cool; colorless to amber liquid when molten (melts at 52°C). Acrid, choking, irritating odor.
| Also known as | 2,5-Furandionecis-Butenedioic anhydrideToxilic anhydrideDihydro-2,5-dioxofuran |
| CAS Number | 108-31-6 |
| Appearance | White to pale yellow crystalline solid when cool; colorless to amber liquid when molten (melts at 52°C). Acrid, choking, irritating odor. |
| Flash Point | 110°C (230°F) - combustible |
| Boiling Point | 202°C (396°F) |
| Vapor Density | 3.4 (heavier than air) |
| Water Reactivity | Reacts with water to form maleic acid, generating heat; reaction is not violent but produces corrosive solution |
Fireground Response Guidance — UN 2215
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, mist, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing selected from SDS; Level A may be needed for heavy vapor or unknown concentrations.
Isolation & Evacuation
First Actions for a UN 2215 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, dust, mist, smoke or fumes and avoid skin or eye contact.
- Avoid unnecessary water contact with released product unless incident command confirms a compatible control use.
- Do not touch damaged containers or 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 release area and expand the perimeter for fire involvement, vapor spread, dust generation, water reaction or unknown product identity.
- Use ERG Guide 156, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 2215 — Maleic anhydride, moltenUse 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.