UN 1661 — Nitroanilines
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1661 is Nitroanilines, a toxic hazardous material assigned to ERG Guide 153. Responders should verify the exact product with shipping papers, package markings and SDS before close action.
Hazard overview: UN 1661 presents toxic exposure hazards by inhalation, ingestion or skin contact. Fire, decomposition or runoff may produce toxic contamination and require air monitoring, isolation and decontamination.
Response guidance: For a UN 1661 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 dust or vapor exposure, control runoff and choose entry or cleanup actions based on monitoring, SDS and local SOP.
Firefighter training notes: Training for UN 1661 should emphasize toxic exposure routes, air monitoring, PPE selection, decontamination and preventing contaminated runoff. Use ERG 153, SDS and local SOP.
Regulatory context: Nitroanilines 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: Nitroanilines should be stored in tightly closed compatible containers in a secure toxic-material area according to SDS and local hazardous materials procedures.
UN 1661 Quick Details
Common Hazards of UN 1661
- TOXIC material; may be harmful or fatal if inhaled, ingested or absorbed through skin.
- Avoid breathing vapors, dust or mist and avoid skin or eye contact.
- Fire may produce irritating, corrosive and/or toxic gases.
- Runoff may carry toxic contamination and may pollute waterways.
- Containers may rupture or fail when heated.
- Specific toxicity and absorption risk should be confirmed from shipping papers and SDS.
Chemical Identity & Physical Properties
Yellow to orange crystalline solid or powder with a slight aromatic odor. Exists as three isomers (ortho, meta, para) with slightly different colors ranging from yellow-orange to red-orange.
| Also known as | nitroanilinemononitroanilineaminonitrobenzenenitrobenzenamineortho-nitroanilinemeta-nitroanilinepara-nitroaniline |
| Appearance | Yellow to orange crystalline solid or powder with a slight aromatic odor. Exists as three isomers (ortho, meta, para) with slightly different colors ranging from yellow-orange to red-orange. |
| Flash Point | 158-199C (316-390F) depending on isomer |
| Boiling Point | 285-332C (545-630F) depending on isomer |
| Vapor Density | 4.8 (heavier than air) |
| Water Reactivity | No significant reaction with water; slightly soluble |
Fireground Response Guidance — UN 1661
Extinguishing Media
PPE Requirements
Use protective equipment selected from SDS, monitoring results and incident command.
Isolation & Evacuation
First Actions for a UN 1661 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 all skin or eye contact.
- Do not touch or walk through spilled material unless properly trained and wearing appropriate protective equipment.
- Avoid creating dust clouds or spreading contaminated liquid, powder, solution, runoff or debris.
- 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 dust, vapor, fire involvement 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 1661 — NitroanilinesUse 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.