UN 2678 — Rubidium hydroxide, solid
Placard: Corrosive. ERG Guide 154. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2678 is Rubidium hydroxide, solid, a strongly corrosive alkali hydroxide solid assigned to ERG Guide 154. Moisture creates caustic heat and runoff hazards.
Hazard overview: STRONGLY CORROSIVE alkali hydroxide solid; dust or solution can cause severe burns. Hygroscopic solid absorbs moisture and forms strongly alkaline corrosive solution. Dissolves in water with heat release; splattering or steam generation may occur.
Response guidance: For UN 2678, isolate the area, avoid mist or splash exposure and use SCBA where vapor/mist is present. Contain alkaline runoff, keep acids away and verify concentration controls with SDS and ERG 154.
Firefighter training notes: Training for UN 2678 should emphasize caustic burns, mist/vapor control, heat of dilution, acid incompatibility, decontamination and alkaline runoff containment. Use ERG 154, SDS and local SOP.
Regulatory context: Rubidium hydroxide, solid is regulated as a hazardous material for transport and emergency response. Storage, exposure, spill reporting, waste and fire-code duties depend on quantity, concentration and jurisdiction; verify shipping papers, SDS and local authority requirements.
Storage & handling: Rubidium hydroxide, solid should be stored in compatible corrosion-resistant containers with ventilation, secondary containment and segregation from acids, metals where incompatible and reactive materials.
UN 2678 Quick Details
Common Hazards of UN 2678
- STRONGLY CORROSIVE alkali hydroxide solid; dust or solution can cause severe burns.
- Hygroscopic solid absorbs moisture and forms strongly alkaline corrosive solution.
- Dissolves in water with heat release; splattering or steam generation may occur.
- Non-combustible, but contact with some metals may generate flammable hydrogen gas.
- Runoff may be strongly alkaline and harmful to waterways.
- Containers may fail when heated or exposed to moisture.
- Avoid dust generation and direct unprotected contact.
Chemical Identity & Physical Properties
White to grayish-white crystalline solid or pellets. Odorless. Hygroscopic (absorbs moisture from air). Highly caustic alkali metal hydroxide.
| Also known as | Rubidium hydroxideRubidium hydrateRubidium(I) hydroxideRbOH |
| CAS Number | 1310-82-3 |
| Appearance | White to grayish-white crystalline solid or pellets. Odorless. Hygroscopic (absorbs moisture from air). Highly caustic alkali metal hydroxide. |
| Flash Point | Not applicable (non-combustible solid) |
| Boiling Point | Not applicable (decomposes before boiling) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Dissolves exothermically in water generating significant heat; may cause spattering or steam generation. Forms strongly alkaline corrosive solution. |
Fireground Response Guidance — UN 2678
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, mist, dust, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing.
Isolation & Evacuation
First Actions for a UN 2678 Incident
- Call 911 and the emergency response number on the shipping paper, if available.
- Keep unauthorized personnel away and establish incident command.
- Stay upwind, uphill and upstream.
- Avoid breathing vapor, dust, mist, smoke or fumes and avoid skin or eye contact.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated liquid, dust, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 154, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 2678 — Rubidium hydroxide, solidUse 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.