UN 3206 — Alkali metal alcoholates, selfheating, corrosive, n.o.s.
Placard: Spontaneously Combustible. ERG Guide 136. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3206 covers reactive metal alcoholates/alkoxides that can be pyrophoric, corrosive and dangerous when wet. Product identity controls the response.
Hazard overview: These materials may ignite in moist air and can react violently with water. They can also cause corrosive injury and release irritating fumes in fire.
Response guidance: Keep containers dry, isolate the area and prevent water contact. Use dry sand, soda ash or compatible Class D/dry chemical media, and do not use water, foam, CO2 or halogenated agents unless approved by the SDS.
Firefighter training notes: Train crews to recognize dangerous-when-wet placards, keep product dry, deny entry to low areas, and avoid using hose streams on unknown reactive solids or liquids.
Regulatory context: Class 4 dangerous-when-wet entries require strict moisture control, compatible packaging and product-specific SDS verification during transport and storage.
Storage & handling: Store dry, tightly sealed and away from water, humidity, sprinklers, acids and incompatible extinguishing agents. Keep spill control media dry and dedicated.
UN 3206 Quick Details
Common Hazards of UN 3206
- Alkoxide/alcoholate material is self-heating and corrosive and can ignite after exposure to air or moisture.
- Contact with water can release heat and flammable hydrogen or alcohol vapors.
- Material is corrosive to skin, eyes and some metals.
- Burning material may re-ignite and produce dense irritating fumes.
- Containers may rupture when heated or contaminated with moisture.
- Do not allow runoff or wet cleanup media to contact the product.
- Exact metal alcoholate must be verified from SDS and shipping papers.
Chemical Identity & Physical Properties
White to off-white powder or solid, may be transported as molten liquid. Pungent odor. Pyrophoric - ignites spontaneously when exposed to air.
| Also known as | Sodium methylatePotassium ethoxideAlkali metal alkoxidesMetal alcoholatesSodium methoxidePotassium tert-butoxide |
| Appearance | White to off-white powder or solid, may be transported as molten liquid. Pungent odor. Pyrophoric - ignites spontaneously when exposed to air. |
| Flash Point | Not applicable (pyrophoric solid/liquid - self-ignites on air contact) |
| Boiling Point | Variable depending on specific alcoholate; typically decomposes before boiling |
| Vapor Density | Not applicable (solid, or molten liquid with negligible vapor pressure) |
| Water Reactivity | Reacts violently with water, releasing heat and flammable hydrogen gas; may ignite spontaneously |
Fireground Response Guidance — UN 3206
Extinguishing Media
PPE Requirements
Use SCBA and full chemical-resistant protective clothing. Level A may be needed for unknown concentration, fire involvement or significant pyrophoric release.
Isolation & Evacuation
First Actions for a UN 3206 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command before close approach.
- Stay upwind, uphill and upstream; avoid low areas where vapors or gases may collect.
- Avoid breathing vapors, dust, smoke or decomposition products and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without appropriate PPE and monitoring.
- Ventilate confined spaces only if trained, equipped and authorized by incident command.
- Use ERG, SDS, shipping papers and atmospheric/radiation monitoring for final isolation and control decisions.
📋 Copy & Share Field Card
UN 3206 — Alkali metal alcoholates, selfheating, cUse 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.