UN 1235 — Methylamine, aqueous solution
Placard: Flammable. ERG Guide 132. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1235 is Methylamine, aqueous solution, a flammable amine liquid assigned to ERG Guide 132. It combines vapor fire risk with strong ammonia/fishy vapors that can irritate or burn eyes, skin and the respiratory tract.
Hazard overview: UN 1235 presents flammable vapor, flashback and corrosive/irritating amine exposure hazards. Vapors can collect in low areas and ignite, while liquid or vapor contact can injure tissue.
Response guidance: For a UN 1235 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 1235 should emphasize amine irritation/corrosivity, flammable vapor travel, sewer entry prevention and PPE selection. Common errors include using fire-only PPE for chemical exposure and ignoring alkaline/corrosive runoff. Use ERG 132, SDS and local SOP.
Regulatory context: Methylamine, aqueous solution 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 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: Methylamine, aqueous solution should be stored in tightly closed compatible containers in a cool, dry, well-ventilated flammable-liquid storage area. Keep away from heat, sparks, open flames, oxidizers and incompatible materials, with bonding/grounding, secondary containment and drain protection where required.
UN 1235 Quick Details
Common Hazards of UN 1235
- FLAMMABLE amine liquid; may be ignited by heat, sparks or flames.
- Vapors may form explosive mixtures with air and flash back to the source.
- Amine vapors and liquid may strongly irritate or burn eyes, skin and respiratory tissue.
- Vapors are heavier than air and may collect in low, confined or sewer areas.
- Runoff may create fire, explosion or alkaline/corrosive contamination hazards.
- Fire may produce irritating, corrosive and/or toxic gases.
- Containers may rupture or explode when heated.
Chemical Identity & Physical Properties
Colorless to pale yellow aqueous solution with a strong, pungent, fishy ammonia-like odor. Liquid at room temperature.
| Also known as | MonomethylamineMethanamineAminomethaneMMA solution |
| CAS Number | 74-89-5 |
| Appearance | Colorless to pale yellow aqueous solution with a strong, pungent, fishy ammonia-like odor. Liquid at room temperature. |
| Flash Point | 0C (32F) for 40% solution; -10C (14F) for higher concentrations |
| Boiling Point | Approximately 47-87C (117-189F) depending on concentration |
| Vapor Density | 1.1 (heavier than air) |
| Water Reactivity | Already in aqueous solution; miscible with water in all proportions |
Fireground Response Guidance — UN 1235
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, fire or confined-space exposure. Chemical-resistant gloves, eye/face protection and protective clothing are important because amine liquids and vapors can irritate or burn tissue.
Isolation & Evacuation
First Actions for a UN 1235 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 1235 — Methylamine, aqueous solutionUse 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.