UN 2572 — Phenylhydrazine
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
Phenylhydrazine is a toxic, corrosive combustible material shipped as UN 2572. Responders should prevent contact, control vapor and contain contaminated runoff.
Hazard overview: Phenylhydrazine can cause severe injury through inhalation, ingestion or skin contact. Heating or fire can generate toxic nitrogen oxide fumes and irritating smoke.
Response guidance: Isolate the area, control ignition sources and keep crews upwind. Use alcohol-resistant foam, dry chemical, CO2 or water spray for cooling and fire control as compatible with the SDS.
Firefighter training notes: Train crews on toxic combustible liquid response, decon and runoff control. Include vapor monitoring and ignition source control.
Regulatory context: UN 2572 is transported as Phenylhydrazine, Class 6 toxic material. Confirm package condition, quantity and emergency contacts from shipping papers.
Storage & handling: Store closed in a cool, ventilated toxic/combustible material area away from oxidizers, acids, heat, air and light exposure.
UN 2572 Quick Details
Common Hazards of UN 2572
- Phenylhydrazine is toxic and corrosive; inhalation, ingestion or skin contact can cause severe injury.
- Liquid or crystals can irritate or burn skin and eyes.
- It is combustible and can burn when heated or exposed to flame.
- Fire can produce toxic nitrogen oxides and irritating smoke.
- Vapors may form ignitable mixtures when heated, especially in confined spaces.
- Runoff can be toxic and harmful to waterways.
- Material can darken and degrade on exposure to air and light.
Chemical Identity & Physical Properties
Phenylhydrazine may appear as a yellow to brown oily liquid or crystalline solid with a faint aromatic odor. It darkens on exposure to air and light.
| Also known as | HydrazinobenzenePhenyl hydrazineMonophenylhydrazinePHZ |
| CAS Number | 100-63-0 |
| Appearance | Yellow to brown oily liquid or crystalline solid with a faint aromatic odor. Darkens on exposure to air and light. |
| Flash Point | 88°C (192°F) |
| Boiling Point | 243°C (469°F) - decomposes |
| Vapor Density | 3.7 (heavier than air) |
| Water Reactivity | Soluble in water; no violent reaction but forms toxic solutions |
Fireground Response Guidance — UN 2572
Extinguishing Media
PPE Requirements
Use SCBA for vapor, smoke or unknown atmosphere. Wear chemical-resistant suit, gloves, boots and eye/face protection to prevent contact.
Isolation & Evacuation
First Actions for a UN 2572 Incident
- Call 911 and the emergency response number on the shipping papers.
- Keep unauthorized personnel away and control ignition sources.
- Stay upwind, uphill and upstream of vapor, smoke and runoff.
- Avoid breathing vapor or mist; prevent skin and eye contact.
- Do not touch damaged containers or spilled material without chemical-resistant PPE.
- Ventilate confined spaces only with trained personnel, SCBA and monitoring.
- Use ERG 153, SDS and shipping papers to confirm isolation, decon and medical guidance.
📋 Copy & Share Field Card
UN 2572 — PhenylhydrazineUse 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.