UN 1718 — Acid butyl phosphate
Placard: Corrosive. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1718 is Acid butyl phosphate, a corrosive combustible phosphate liquid assigned to ERG Guide 153. It can injure skin, eyes and respiratory tissue and may burn under fire conditions.
Hazard overview: UN 1718 presents corrosive liquid, combustible fire and contaminated-runoff hazards. Water dilution may generate heat and spread corrosive contamination.
Response guidance: For a UN 1718 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 153. Establish incident command, isolate the area, stay upwind, prevent incompatible contact, control runoff and choose entry or fire-control actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1718 should emphasize corrosive/toxic exposure routes, air monitoring, PPE selection, decontamination, runoff containment and compatible extinguishing decisions. Use ERG 153, SDS and local SOP.
Regulatory context: Acid butyl phosphate 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 concentration, 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: Acid butyl phosphate should be stored in tightly closed compatible containers in a secure, cool, dry, well-ventilated hazardous-material area according to SDS and local procedures.
UN 1718 Quick Details
Common Hazards of UN 1718
- CORROSIVE combustible liquid; inhalation, ingestion or skin contact may cause severe injury.
- Liquid can burn eyes, skin and respiratory tissue.
- Combustible material: may burn but does not ignite readily.
- Water dilution may generate heat and spread corrosive runoff.
- Fire may produce phosphorus oxides and other irritating/corrosive gases.
- Containers may rupture or fail when heated.
- Runoff may be corrosive and environmentally harmful.
Chemical Identity & Physical Properties
Clear to pale yellow liquid with a mild acidic odor. Corrosive liquid at room temperature.
| Also known as | Butyl acid phosphateMonobutyl phosphateButyl dihydrogen phosphatePhosphoric acid butyl ester |
| CAS Number | 12788-93-1 |
| Appearance | Clear to pale yellow liquid with a mild acidic odor. Corrosive liquid at room temperature. |
| Flash Point | 110°C (230°F) |
| Boiling Point | Decomposes before boiling at approximately 200°C (392°F) |
| Vapor Density | Not applicable (low volatility liquid) |
| Water Reactivity | Soluble in water; may generate heat when dissolved but no violent reaction |
Fireground Response Guidance — UN 1718
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for mist, vapor, fire or confined-space exposure. Wear chemical-resistant gloves, boots, eye/face protection and protective clothing selected from SDS for corrosive liquid contact.
Isolation & Evacuation
First Actions for a UN 1718 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, fumes, dust or mist and avoid skin or eye contact.
- Do not touch or walk through 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 leak area and expand the perimeter if vapor, dust, fire involvement, water reaction or unknown concentration is present.
- Use ERG Guide 153, shipping papers, SDS, air monitoring and incident command for protective actions.
📋 Copy & Share Field Card
UN 1718 — Acid butyl phosphateUse 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.