UN 3560 — Tetramethylammonium hydroxide aqueous solution with not less than 25% tetramethylammonium hydroxide
Placard: Corrosive / Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3560 At a Glance
UN 3560 (Tetramethylammonium hydroxide aqueous solution with not less than 25%…) is listed as DOT Class 8 Corrosive / Toxic and is assigned to ERG Guide 153. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
UN 3560 is Tetramethylammonium hydroxide aqueous solution with not less than 25% tetramethylammonium hydroxide, a toxic corrosive alkaline solution assigned to ERG Guide 153. Skin contact, systemic toxicity and caustic runoff are key concerns.
Hazard overview: TOXIC and CORROSIVE tetramethylammonium hydroxide solution; skin contact can cause severe injury and systemic toxicity. Strong alkaline liquid can burn eyes, skin and respiratory tissue. Tetramethylammonium ion exposure can cause serious systemic effects; avoid all unprotected skin contact.
Response guidance: For UN 3560, isolate the spill, prevent skin contact and use SCBA with chemical splash protection. Control caustic/toxic runoff and avoid uncontrolled neutralization under ERG 153.
Firefighter training notes: Training for UN 3560 should emphasize caustic splash control, TMAH systemic toxicity, skin decontamination urgency, SCBA use and runoff containment. Use ERG 153, SDS and local SOP.
Regulatory context: Tetramethylammonium hydroxide aqueous solution with not less than 25% tetramethylammonium hydroxide is regulated as a hazardous material for transport and emergency response. Storage, reporting, exposure, waste and incident-notification duties depend on quantity, concentration, package type and jurisdiction; verify shipping papers, SDS and authority guidance.
Storage & handling: Tetramethylammonium hydroxide aqueous solution with not less than 25% tetramethylammonium hydroxide should be stored in compatible corrosion-resistant containers with secondary containment, restricted access and segregation from acids, oxidizers and incompatible metals/materials.
UN 3560 Quick Details
Common Hazards of UN 3560
- TOXIC and CORROSIVE tetramethylammonium hydroxide solution; skin contact can cause severe injury and systemic toxicity.
- Strong alkaline liquid can burn eyes, skin and respiratory tissue.
- Tetramethylammonium ion exposure can cause serious systemic effects; avoid all unprotected skin contact.
- Mist or aerosol can injure respiratory tissue and contaminate PPE or tools.
- Dilution or neutralization may release heat and cause splattering.
- Runoff may be caustic, toxic and harmful to waterways.
- Fire may produce nitrogen oxides, corrosive/alkaline mist and irritating toxic smoke from packaging or residues.
Chemical Identity & Physical Properties
Clear to slightly yellow viscous liquid with a strong ammonia-like odor. Typically supplied as an aqueous solution at concentrations of 25% or higher.
| Also known as | TMAHTetramethylammonium hydroxideTetrabaseN,N,N-trimethylmethanaminium hydroxideTMAOH |
| CAS Number | 75-59-2 |
| Appearance | Clear to slightly yellow viscous liquid with a strong ammonia-like odor. Typically supplied as an aqueous solution at concentrations of 25% or higher. |
| Flash Point | Not applicable (aqueous solution, concentration dependent) |
| Boiling Point | Approximately 100-130C (212-266F) depending on concentration |
| Vapor Density | Not applicable (aqueous solution) |
| Water Reactivity | No significant reaction; miscible with water, already an aqueous solution |
Fireground Response Guidance — UN 3560
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for mist, fire or confined-space exposure and chemical-resistant splash protection, gloves, boots and eye/face protection.
Isolation & Evacuation
First Actions for a UN 3560 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, gas, mist, smoke or fumes and avoid skin or eye contact.
- Avoid any unprotected skin contact and keep neutralization/dilution controlled because heat and splattering may occur.
- Do not touch damaged containers or spilled material without proper training and PPE.
- Prevent contaminated liquid, runoff and decontamination waste from spreading.
- Ventilate confined spaces only after monitoring and only if properly trained and equipped.
- Use ERG Guide 153, SDS, shipping papers and monitoring to set isolation, evacuation and entry decisions.
📋 Copy & Share Field Card
UN 3560 — Tetramethylammonium hydroxide aqueous soUse 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.