UN 2538 — Nitronaphthalene
Placard: Flammable Solid. ERG Guide 133. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 2538 At a Glance
UN 2538 (Nitronaphthalene) is listed as DOT Class 4 Flammable Solid and is assigned to ERG Guide 133. Use this page to review placard data, common hazards, PPE notes, isolation context, first actions, and related UN numbers.
Nitronaphthalene is a yellow to brown crystalline aromatic solid shipped as UN 2538. For responders, the main concerns are ignition of dust or heated material, toxic fire gases and contaminated runoff.
Hazard overview: Nitronaphthalene should be treated as a flammable solid. It may ignite from heat, sparks or friction, and finely divided dust can burn more aggressively. Fire can generate irritating and toxic nitrogen oxide fumes.
Response guidance: Control ignition sources, isolate the area and keep crews upwind. Use dry chemical, carbon dioxide, foam or water spray as appropriate for the fire and surrounding exposures. Avoid direct handling of spilled solid without chemical-resistant PPE and respiratory protection.
Firefighter training notes: Train crews to recognize flammable solid behavior, dust ignition potential and toxic smoke hazards. Emphasize upwind positioning, ignition control and runoff containment.
Regulatory context: UN 2538 is listed for transport as Nitronaphthalene, Class 4, Flammable Solid. Confirm packaging, quantity and emergency contact information from the shipping papers.
Storage & handling: Store away from heat, sparks, oxidizers and incompatible materials. Keep containers closed, dry and protected from physical damage.
UN 2538 Quick Details
Common Hazards of UN 2538
- Nitronaphthalene is a combustible flammable solid; dust or finely divided material can ignite more easily than lumps or crystals.
- Heat, sparks, open flame, friction or hot surfaces may ignite the material.
- Fire can produce irritating and toxic nitrogen oxide fumes and dense smoke.
- Molten or heated material may cause thermal burns in addition to chemical irritation.
- Dust clouds may burn rapidly if dispersed in air near an ignition source.
- Containers can rupture when heated, especially if exposed to direct flame.
- Contaminated runoff may carry toxic organic material away from the scene.
Chemical Identity & Physical Properties
Nitronaphthalene is typically a yellow to brown crystalline solid with a faint aromatic odor and a melting point near 61°C.
| Also known as | 1-Nitronaphthalenealpha-NitronaphthaleneMononitronaphthaleneNaphthalene mononitrate |
| CAS Number | 86-57-7 |
| Appearance | Yellow to brown crystalline solid with a faint aromatic odor. Solid at room temperature, melting point around 61°C. |
| Flash Point | 158°C (316°F) |
| Boiling Point | 304°C (579°F) |
| Vapor Density | 6.0 (heavier than air) |
| Water Reactivity | No significant reaction with water; slightly soluble |
Fireground Response Guidance — UN 2538
Extinguishing Media
PPE Requirements
Use SCBA for fire, smoke or unknown vapor conditions. Chemical-resistant gloves, eye protection and protective clothing are needed to prevent contact with dust, molten material or contaminated runoff.
Isolation & Evacuation
First Actions for a UN 2538 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 smoke, dust or runoff.
- Avoid breathing dust, vapor or fire gases; avoid skin and eye contact.
- Do not touch spilled material or damaged containers without proper PPE.
- Ventilate confined spaces only if trained, equipped and atmospheric monitoring supports entry.
- Use ERG 133, the SDS and shipping papers to set isolation, evacuation and cleanup actions.
📋 Copy & Share Field Card
UN 2538 — NitronaphthaleneUse 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.