☣️ UN 1334 • CLASS 4

UN 1334 — Naphthalene, refined

Placard: Flammable Solid. ERG Guide 133. 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.

UN 1334 is Naphthalene, refined, a Class 4 flammable organic solid assigned to ERG Guide 133. It is best known as refined naphthalene, a mothball-like solid that can sublime and create irritating vapors.

Hazard overview: UN 1334 presents flammable solid, vapor irritation and smoke hazards. Naphthalene can give off aromatic vapors in warm or enclosed areas, and fire may produce irritating or toxic smoke.

Response guidance: For a UN 1334 incident, responders should verify the product with shipping papers, package markings, SDS and ERG Guide 133. Establish incident command, isolate the area, stay upwind, avoid unnecessary disturbance of powder or damaged packaging, and use only extinguishing agents compatible with the specific material.

Firefighter training notes: Training for UN 1334 should emphasize dust fire behavior, rapid surface burning, smoke exposure, compatible extinguishment and avoiding dust cloud generation. Use ERG 133, SDS and local SOP.

Regulatory context: Naphthalene, refined 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, 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: Naphthalene, refined should be stored in compatible containers in a cool, dry, well-ventilated area away from heat, sparks, open flames, oxidizers and incompatible materials. Prevent dust release, friction, impact and unauthorized access.

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UN 1334 Quick Details

UN 1334
Product name: Naphthalene, refined
DOT Class: 4
Placard type: Flammable Solid
ERG Guide: 133 (check current ERG)
Initial isolation: ERG 133: isolate 25m all directions initially; for large spills consider 50m isolation and evacuation of immediate area if fire develops

Common Hazards of UN 1334

  • FLAMMABLE/COMBUSTIBLE organic solid; may be ignited by heat, sparks or flames.
  • Vapors from subliming material may be heavier than air and may irritate or harm responders in enclosed spaces.
  • Dust or powder may burn rapidly if dispersed.
  • Fire may produce irritating or toxic smoke.
  • Skin contact or inhalation exposure should be minimized; verify toxicity from SDS.
  • Runoff from fire control may carry contaminated residue.
  • Containers or bags may fail when exposed to fire.

Chemical Identity & Physical Properties

White crystalline solid with a distinctive mothball odor. Sublimes at room temperature, producing characteristic aromatic vapors.

Also known asmothballswhite tarnaphthalintar camphormoth flakes
CAS Number91-20-3
AppearanceWhite crystalline solid with a distinctive mothball odor. Sublimes at room temperature, producing characteristic aromatic vapors.
Flash Point79-87C (174-189F)
Boiling Point218C (424F)
Vapor Density4.4 (heavier than air)
Water ReactivityInsoluble in water, no significant reaction
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.

Fireground Response Guidance — UN 1334

Extinguishing Media

Use water spray, fog, foam, dry chemical or CO2 only when compatible with the specific material and incident command; avoid spreading dust or burning material.

PPE Requirements

⚠️ Level C minimum; SCBA for enclosed spaces or large spills; avoid skin contact due to absorption risk

Use SCBA for fire, smoke, dust or confined-space exposure. Gloves, eye protection and protective clothing should be selected from SDS; avoid dust generation and contaminated residue contact.

Isolation & Evacuation

ERG 133: isolate 25m all directions initially; for large spills consider 50m isolation and evacuation of immediate area if fire develops
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 133).

First Actions for a UN 1334 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.
  • Eliminate ignition sources if it is safe to do so.
  • Avoid creating dust clouds or spreading powder during movement or cleanup.
  • Ventilate closed spaces before entering, but only if properly trained, equipped and authorized by incident command.
  • Isolate the spill or fire area and expand the perimeter if large quantities, dust clouds or fire involvement are present.
  • Use ERG Guide 133, shipping papers, SDS and incident command for protective actions and entry decisions.
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📋 Copy & Share Field Card

UN 1334 — Naphthalene, refined
HAZMAT RADIO NOTE — UN 1334 Product: Naphthalene, refined Class 4 / Flammable Solid / ERG 133 PPE: Level C minimum; SCBA for enclosed spaces or large spills; avoid skin contact due to absorption risk ISOLATION: ERG 133: isolate 25m all directions initially; for large spills consider 50m isolation and evacuation of immediate area if fire develops ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO

Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.

SMS WhatsApp
=== IC HAZMAT BRIEFING === UN 1334 — Naphthalene, refined Class: 4 | Placard: Flammable Solid | ERG Guide: 133 Appearance: White crystalline solid with a distinctive mothball odor. Sublimes at room temperature, producing characteristic aromatic vapors. Water Reactivity: Insoluble in water, no significant reaction Extinguishing: Use water spray, fog, foam, dry chemical or CO2 only when compatible with the specific material and incident command; avoid spreading dust or burning material. PPE: Level C minimum; SCBA for enclosed spaces or large spills; avoid skin contact due to absorption risk Isolation: ERG 133: isolate 25m all directions initially; for large spills consider 50m isolation and evacuation of immediate area if fire develops — Key Hazards — • FLAMMABLE/COMBUSTIBLE organic solid; may be ignited by heat, sparks or flames. • Vapors from subliming material may be heavier than air and may irritate or harm responders in enclosed spaces. • Dust or powder may burn rapidly if dispersed. — First Actions — • 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. • Eliminate ignition sources if it is safe to do so. SOURCE: allfirefighter.com/hazmat/un/naphthalene-refined-un-1334 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.

SMS (short)
UN1334 Naphthalene, refined Cls4 ERG133 | allfirefighter.com/hazmat/un/naphthalene-refined-un-1334SMS / 160 CHAR

Use for: Quick text to command or incoming units. Fits in a single SMS.

⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions. Page: https://allfirefighter.com/hazmat/un/naphthalene-refined-un-1334

Related UN Numbers in Class 4

Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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Frequently Asked Questions about UN 1334

UN 1334 is Naphthalene, refined, a hazardous material assigned to ERG Guide 133.

Yes. Refined naphthalene is a flammable solid and can burn when heated or exposed to flame.

ERG Guide 133 applies to UN 1334 for initial isolation, protective actions and first response guidance.

UN 1334 presents flammable solid, vapor irritation and smoke hazards. Naphthalene can give off aromatic vapors in warm or enclosed areas, and fire may produce irritating or toxic smoke.

White crystalline solid with a distinctive mothball odor. Sublimes at room temperature, producing characteristic aromatic vapors.
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.