☣️ UN 3342 • CLASS 4

Xanthates

Placard: Spontaneously Combustible. 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 3342
Class: 4
Placard type: Spontaneously Combustible
ERG: Guide 135 (check current ERG)
Isolation: ERG 135: isolate spill/leak area 50m all directions; if tank/rail car involved in fire, isolate 800m all directions
Chemical & Response Details
Also known asXanthatesXanthic acid saltsDithiocarbonatesCellulose xanthateAlkyl xanthates
AppearanceYellow to pale amber crystalline solids or powders with a characteristic unpleasant odor. Hygroscopic materials that may decompose in moist air.
Flash PointNot applicable (spontaneously combustible solid)
Boiling PointNot applicable (decomposes before boiling)
Vapor DensityNot applicable (solid)
Water ReactivityReacts with moisture and acids to release highly flammable carbon disulfide vapor; avoid water contact
ExtinguishingDry chemical, dry sand, soda ash; do not use water or foam
PPE⚠️ Level B minimum; SCBA required; chemical-resistant gloves and suit; avoid moisture contamination
IsolationERG 135: isolate spill/leak area 50m all directions; if tank/rail car involved in fire, isolate 800m all directions
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • Flammable/combustible material.
  • May ignite on contact with moist air or moisture.
  • May burn rapidly with flare-burning effect.
  • Some react vigorously or explosively on contact with water.
  • Some may decompose explosively when heated or involved in a fire.
  • May re-ignite after fire is extinguished.
  • Runoff may create fire or explosion hazard.
  • Containers may explode when heated.
First actions (field-minded)
  • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
  • Stay upwind, uphill and/or upstream.
  • Keep unauthorized personnel away.
  • Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
  • For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.
  • For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind
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UN 3342 — Xanthates
HAZMAT RADIO NOTE — UN 3342 Product: Xanthates Class 4 / Spontaneously Combustible / ERG 135 PPE: Level B minimum; SCBA required; chemical-resistant gloves and suit; avoid moisture contamination ISOLATION: ERG 135: isolate spill/leak area 50m all directions; if tank/rail car involved in fire, isolate 800m all directions 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 3342 — Xanthates Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 135 Appearance: Yellow to pale amber crystalline solids or powders with a characteristic unpleasant odor. Hygroscopic materials that may decompose in moist air. Water Reactivity: Reacts with moisture and acids to release highly flammable carbon disulfide vapor; avoid water contact Extinguishing: Dry chemical, dry sand, soda ash; do not use water or foam PPE: Level B minimum; SCBA required; chemical-resistant gloves and suit; avoid moisture contamination Isolation: ERG 135: isolate spill/leak area 50m all directions; if tank/rail car involved in fire, isolate 800m all directions — Key Hazards — • Flammable/combustible material. • May ignite on contact with moist air or moisture. • May burn rapidly with flare-burning effect. — First Actions — • CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper • Stay upwind, uphill and/or upstream. • Keep unauthorized personnel away. • Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters SOURCE: allfirefighter.com/hazmat/un/3342 | Always use current ERG + SOP/SOGIC BRIEFING

Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.

SMS (short)
UN3342 Xanthates Cls4 ERG135 | ERG 135: isolate spill/leak area 50m all directions; if tank/rail car involved i | allfirefighter.com/hazmat/un/3342SMS / 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/3342
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
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FAQ

Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated.

CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Stay upwind, uphill and/or upstream. Keep unauthorized personnel away.

Level B minimum; SCBA required; chemical-resistant gloves and suit; avoid moisture contamination

No. This is a training/quick-reference aid only. Always consult the current ERG Guide 135 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.