UN 2574 — Tricresyl phosphate
Placard: Toxic. ERG Guide 151. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Tricresyl phosphate is a toxic, viscous organophosphate ester. Responders should focus on preventing skin absorption, inhalation of mist and contaminated runoff.
Hazard overview: The material is not a fast-evaporating flammable liquid, but it can burn when heated and can produce toxic decomposition products. Significant dermal or ingestion exposure may cause serious systemic effects, including delayed neurological injury depending on isomer composition.
Response guidance: Keep personnel out of spill areas, stop the release only from a protected position and prevent entry into drains or waterways. Use foam, dry chemical or CO2 for fire and cool containers with water spray from a safe distance.
Firefighter training notes: Train crews to recognize that low vapor pressure does not remove the toxicity hazard. Emphasize dermal protection, runoff control and decontamination of oily residues.
Regulatory context: UN 2574 is transported as Tricresyl phosphate, Class 6 toxic material. Confirm packing details, concentration and any reportable quantity requirements from shipping papers and SDS.
Storage & handling: Store in closed containers away from strong oxidizers, heat and drains. Secondary containment should be used where releases could reach waterways.
UN 2574 Quick Details
Common Hazards of UN 2574
- Toxic organophosphate ester; harmful by ingestion, inhalation of mist or prolonged skin contact.
- Some tricresyl phosphate isomers are associated with delayed neurotoxic effects after significant exposure.
- Combustible liquid; it may burn when heated even though it has a relatively high flash point.
- Fire may produce irritating or toxic phosphorus oxides, carbon monoxide and phenolic decomposition products.
- Vapors or mist can irritate eyes, skin and respiratory tract.
- Runoff from fire control or spills may contaminate waterways and should be controlled.
- Containers may rupture when heated.
Chemical Identity & Physical Properties
Tricresyl phosphate is typically a colorless to pale yellow oily liquid with low volatility and a mild phenolic odor. Its viscosity can make surface contamination persistent.
| Also known as | TCPTritolyl phosphateTri-o-cresyl phosphatePhosphoric acid tricresyl esterTricresylphosphate |
| CAS Number | 1330-78-5 |
| Appearance | Colorless to pale yellow oily liquid with a mild phenolic odor. Viscous consistency at room temperature. |
| Flash Point | 225°C (437°F) |
| Boiling Point | 410°C (770°F) with decomposition |
| Vapor Density | 11.2 (much heavier than air) |
| Water Reactivity | No violent water reaction expected; poorly soluble and may float or spread on water. |
Fireground Response Guidance — UN 2574
Extinguishing Media
PPE Requirements
Wear SCBA where vapors, mist or fire gases may be present. Use chemical-resistant gloves, boots and suit material compatible with organophosphate esters; avoid any unprotected skin contact.
Isolation & Evacuation
First Actions for a UN 2574 Incident
- Call 911 and the emergency response number shown on shipping papers; confirm the material with ERG, SDS and container markings.
- Keep unauthorized personnel away and establish hot, warm and cold zones before entry.
- Stay upwind, uphill and upstream; avoid low areas where vapors, dust or runoff may collect.
- Avoid breathing vapors, dust, mist or decomposition products and prevent skin or eye contact.
- Do not touch damaged packages or containers unless properly trained and wearing suitable chemical PPE.
- Ventilate confined spaces only after atmospheric monitoring and only with trained, equipped personnel.
- Use ERG Guide 151, SDS, shipping papers and monitoring results for isolation, PPE and fire-control decisions.
📋 Copy & Share Field Card
UN 2574 — Tricresyl 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.