UN 3451 — Toluidines, solid
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3451 Toluidines, solid is assigned to ERG Guide 153. The exact risk depends on the shipment form, concentration and SDS, but responders should verify shipping papers before committing crews.
Hazard overview: Primary hazards for UN 3451 include: TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.; Vapors, dusts, or molten material may irritate eyes and respiratory passages.; Contact with molten substance may cause severe burns to skin and eyes. Control ignition sources, avoid direct contact and keep personnel upwind.
Response guidance: For a UN 3451 incident, isolate the area, deny entry, stay upwind and use ERG Guide 153 with the shipping papers or SDS. Use compatible extinguishing media only and prevent contaminated runoff from spreading.
UN 3451 Quick Details
Common Hazards of UN 3451
- TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.
- Vapors, dusts, or molten material may irritate eyes and respiratory passages.
- Contact with molten substance may cause severe burns to skin and eyes.
- Avoid any skin contact.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.
- Combustible material: may burn but does not ignite readily.
- When heated, vapors may form explosive mixtures with air, creating indoor, outdoor and sewer explosion hazards.
Chemical Identity & Physical Properties
UN 3451 is described as: White to pale yellow or reddish-brown crystalline solid or liquid at room temperature. Aniline-like odor. May darken on exposure to air and light.
| Also known as | methylanilineaminotoluenetoluidine isomersmethylbenzenamine |
| Appearance | White to pale yellow or reddish-brown crystalline solid or liquid at room temperature. Aniline-like odor. May darken on exposure to air and light. |
| Flash Point | 85-87C (185-189F) depending on isomer |
| Boiling Point | 200-203C (392-397F) depending on isomer |
| Vapor Density | 3.7 (heavier than air) |
| Water Reactivity | No significant reaction, slightly soluble in water |
Fireground Response Guidance — UN 3451
Extinguishing Media
PPE Requirements
PPE guidance for UN 3451: Level B minimum; SCBA required; chemical-resistant suit and gloves; avoid all skin contact due to absorption hazard
Isolation & Evacuation
First Actions for a UN 3451 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.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters.
- For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
- For non-highlighted materials, increase the immediate precautionary distance in the downwind direction as conditions require.
📋 Copy & Share Field Card
UN 3451 — Toluidines, solidUse 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.