UN 1902 — Diisooctyl acid phosphate
Placard: Corrosive. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1902 is Diisooctyl acid phosphate, a corrosive viscous acid phosphate liquid assigned to ERG Guide 153. It can cling to skin and surfaces and may burn under fire conditions.
Hazard overview: UN 1902 presents corrosive contact, combustible liquid, phosphorus oxide fire products and contaminated-runoff hazards. Water dilution can spread corrosive liquid.
Response guidance: For a UN 1902 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 1902 should emphasize exposure routes, air monitoring, PPE selection, decontamination, runoff containment and ERG/SDS verification. Use ERG 153, SDS and local SOP.
Regulatory context: Diisooctyl acid 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 formulation, concentration, 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: Diisooctyl acid phosphate should be stored in compatible corrosion-resistant containers with secondary containment, away from incompatible chemicals, heat and unauthorized access. Follow SDS for oxidizers, acids, bases, solvents or toxic ingredients in the specific product.
UN 1902 Quick Details
Common Hazards of UN 1902
- CORROSIVE combustible acid phosphate liquid; inhalation, ingestion or skin/eye contact may cause severe injury.
- Viscous liquid can cling to skin, tools and surfaces and prolong exposure.
- Combustible material: may burn but does not ignite readily.
- Water dilution may generate heat and spread corrosive runoff.
- Fire may produce phosphorus oxides and irritating/corrosive gases.
- Runoff may be corrosive and environmentally harmful.
- Containers may rupture or fail when heated.
Chemical Identity & Physical Properties
Clear to pale yellow viscous liquid with mild odor. Oily consistency at room temperature.
| Also known as | Bis(2-ethylhexyl) phosphateDi(2-ethylhexyl) phosphoric acidHDEHPD2EHPADiisooctyl orthophosphate |
| CAS Number | 27215-10-7 |
| Appearance | Clear to pale yellow viscous liquid with mild odor. Oily consistency at room temperature. |
| Flash Point | 196°C (385°F) |
| Boiling Point | Decomposes before boiling; approximately 150°C (302°F) at reduced pressure |
| Vapor Density | Not applicable (negligible vapor pressure at ambient temperature) |
| Water Reactivity | No significant reaction; slightly soluble in water, may hydrolyze slowly |
Fireground Response Guidance — UN 1902
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 selected from SDS for corrosive contact.
Isolation & Evacuation
First Actions for a UN 1902 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, mist or spray 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 1902 — Diisooctyl acid 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.