UN 1673 — Phenylenediamines
Placard: Toxic. ERG Guide 153. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 1673 is Phenylenediamines, a toxic aromatic amine material assigned to ERG Guide 153. Dust, skin contact and contaminated runoff are the main responder concerns.
Hazard overview: UN 1673 presents toxic dust, skin absorption, sensitization and toxic smoke hazards. Fire may produce nitrogen oxide smoke, and contaminated dust can spread on clothing and tools.
Response guidance: For a UN 1673 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 1673 should emphasize aromatic amine dust exposure, sensitization/skin absorption, PPE selection, decontamination and runoff containment. Use ERG 153, SDS and local SOP.
Regulatory context: Phenylenediamines 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: Phenylenediamines 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 1673 Quick Details
Common Hazards of UN 1673
- TOXIC aromatic amine solid; inhalation, ingestion or skin absorption may cause severe injury.
- May cause sensitization or serious skin and respiratory irritation depending on isomer and exposure.
- Combustible solid: may burn but does not ignite readily.
- Dust or molten material may injure eyes, skin and respiratory tissue.
- Fire may produce toxic nitrogen oxides and irritating smoke.
- Runoff may carry toxic contamination to drains or waterways.
- Avoid dust and all unnecessary skin contact.
Chemical Identity & Physical Properties
Colorless to pale yellow or brown crystalline solid with a faint amine-like odor. Darkens on exposure to air. Exists as three isomers (ortho, meta, para).
| Also known as | BenzenediamineDiaminobenzenePDAp-Phenylenediaminem-Phenylenediamineo-Phenylenediamine |
| Appearance | Colorless to pale yellow or brown crystalline solid with a faint amine-like odor. Darkens on exposure to air. Exists as three isomers (ortho, meta, para). |
| Flash Point | 156C (313F) for para-isomer |
| Boiling Point | 267C (513F) for para-isomer, decomposes |
| Vapor Density | Not applicable (solid at room temperature) |
| Water Reactivity | No significant reaction with water, but may dissolve slowly |
Fireground Response Guidance — UN 1673
Extinguishing Media
PPE Requirements
Use positive-pressure SCBA for dust, vapor, fire or confined-space exposure. Chemical-resistant gloves, eye/face protection and protective clothing should be selected from SDS; avoid skin contact and contaminated dust.
Isolation & Evacuation
First Actions for a UN 1673 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 1673 — PhenylenediaminesUse 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.