UN 1663 — Nitrophenols
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1663 is Nitrophenols, a toxic nitroaromatic material assigned to ERG Guide 153. It may be solid or liquid, but skin absorption, toxic smoke and contaminated runoff are key responder concerns.
Hazard overview: UN 1663 presents toxic skin, inhalation and ingestion hazards. It may burn or decompose under fire conditions, producing toxic nitrogen oxide smoke; molten or liquid material can also injure skin.
Response guidance: For a UN 1663 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 1663 should emphasize nitroaromatic toxicity, skin absorption, molten/liquid exposure, toxic smoke and runoff containment. Use ERG 153, SDS and local SOP.
Regulatory context: Nitrophenols 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: Nitrophenols should be stored in tightly closed compatible containers in a secure, cool, dry, well-ventilated toxic-material area away from heat, ignition sources, oxidizers, acids/bases where incompatible and unauthorized access. Prevent dust release, skin contact and contaminated runoff.
UN 1663 Quick Details
Common Hazards of UN 1663
- TOXIC nitroaromatic material; inhalation, ingestion or skin absorption may cause severe injury.
- Combustible material: may burn but does not ignite readily.
- Dust, vapor, solution or molten/liquid contact may injure eyes, skin and respiratory tissue.
- Heating or fire may produce toxic nitrogen oxides and irritating smoke.
- Runoff may carry toxic contamination to drains or waterways.
- Containers may rupture or fail when heated.
- Avoid skin contact because absorption may be significant for some nitroaromatic compounds.
- Phenolic nitro compounds can be systemically toxic through skin exposure; molten material can also burn skin.
Chemical Identity & Physical Properties
Yellow to light brown crystalline solid with a sweet, musty odor. Exists as ortho-, meta-, and para-isomers with varying melting points.
| Also known as | MononitrophenolsNitrophenol isomersHydroxylnitrobenzenePhenol nitro derivatives |
| Appearance | Yellow to light brown crystalline solid with a sweet, musty odor. Exists as ortho-, meta-, and para-isomers with varying melting points. |
| Flash Point | Not applicable (combustible solid) |
| Boiling Point | Varies by isomer: 214-279C (417-534F) with decomposition |
| Vapor Density | Not applicable (solid at room temperature) |
| Water Reactivity | Slightly soluble in water, no violent reaction. May form acidic solutions. |
Fireground Response Guidance — UN 1663
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for vapor, dust, fire or confined-space exposure. Chemical-resistant gloves, eye/face protection and protective clothing should be selected from SDS because skin absorption may be significant.
Isolation & Evacuation
First Actions for a UN 1663 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.
- Keep vapors and runoff out of drains, sewers and low areas where practical.
- 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 1663 — NitrophenolsUse 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.