☣️ UN 2304 • CLASS 4
Naphthalene, molten
Placard: Flammable Solid. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
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Quick details
UN 2304
Class: 4
Placard type: Flammable Solid
ERG: Guide 133 (check current ERG)
Isolation: ERG 133: isolate spill area 50m in all directions; for large spills consider initial evacuation 300m downwind
Chemical & Response Details
| Also known as | naphthalenewhite tarmoth ballstar camphornaphthenealbocarbon |
| CAS Number | 91-20-3 |
| Appearance | White crystalline solid at room temperature with a strong mothball odor. When molten, appears as a clear to pale yellow liquid above 80°C (176°F). |
| Flash Point | 79-87°C (174-189°F) |
| Boiling Point | 218°C (424°F) |
| Vapor Density | 4.4 (heavier than air) |
| Water Reactivity | No significant reaction; insoluble in water |
| Extinguishing | Dry chemical, CO2, water spray, regular foam |
| PPE | ⚠️ Level B minimum; SCBA and full protective clothing required due to toxic vapors and burn hazard from molten material |
| Isolation | ERG 133: isolate spill area 50m in all directions; for large spills consider initial evacuation 300m downwind |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Flammable/combustible material.
- May be ignited by friction, heat, sparks or flames.
- Some may burn rapidly with flare-burning effect.
- Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence.
- Substance may be transported in a molten form at a temperature that may be above its flash point.
- May re-ignite after fire is extinguished.
- Fire may produce irritating and/or toxic gases.
- Contact may cause burns to skin and eyes.
First actions (field-minded)
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Isolate spill or leak area for at least 25 meters (75 feet) in all directions.
- Consider initial downwind evacuation for at least 100 meters (330 feet).
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UN 2304 — Naphthalene, molten HAZMAT RADIO NOTE — UN 2304
Product: Naphthalene, molten
Class 4 / Flammable Solid / ERG 133
PPE: Level B minimum; SCBA and full protective clothing required due to toxic vapors and burn hazard from molten material
ISOLATION: ERG 133: isolate spill area 50m in all directions; for large spills consider initial evacuation 300m downwind
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 2304 — Naphthalene, molten
Class: 4 | Placard: Flammable Solid | ERG Guide: 133
Appearance: White crystalline solid at room temperature with a strong mothball odor. When molten, appears as a clear to pale yellow liquid above 80°C (176°F).
Water Reactivity: No significant reaction; insoluble in water
Extinguishing: Dry chemical, CO2, water spray, regular foam
PPE: Level B minimum; SCBA and full protective clothing required due to toxic vapors and burn hazard from molten material
Isolation: ERG 133: isolate spill area 50m in all directions; for large spills consider initial evacuation 300m downwind
— Key Hazards —
• Flammable/combustible material.
• May be ignited by friction, heat, sparks or flames.
• Some may burn rapidly with flare-burning effect.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Isolate spill or leak area for at least 25 meters (75 feet) in all directions.
SOURCE: allfirefighter.com/hazmat/un/2304 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN2304 Naphthalene, molten Cls4 ERG133 | ERG 133: isolate spill area 50m in all directions; for large spills consider ini | allfirefighter.com/hazmat/un/2304SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS. Includes link to full page.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/2304
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FAQ
Flammable/combustible material. May be ignited by friction, heat, sparks or flames. Some may burn rapidly with flare-burning effect. Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence. Substance may be transported in a molten form at a temperature that may be above its flash point. May re-ignite after fire is extinguished. Fire may produce irritating and/or toxic gases. Contact may cause burns to skin and eyes.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.
Level B minimum; SCBA and full protective clothing required due to toxic vapors and burn hazard from molten material
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 133 and your department SOP/SOG for incident-specific protective actions.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles. This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.