☣️ UN 3542 • CLASS 4

Articles containing a substance liable to spontaneous combustion, n.o.s.

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 3542
Class: 4
Placard type: Spontaneously Combustible
ERG: Guide 135 (check current ERG)
Isolation: ERG 135: isolate spill area 25m in all directions; for large spills consider initial evacuation 100m in all directions
Chemical & Response Details
Also known asSelf-heating articlesPyrophoric articlesSpontaneously combustible articlesArticles containing self-reactive substances
AppearanceVariable appearance depending on the specific article and substance contained. Typically solid articles that contain materials capable of spontaneous ignition when exposed to air or moisture at ambient temperatures.
Flash PointNot applicable (spontaneously combustible)
Boiling PointNot applicable (articles/solids)
Vapor DensityNot applicable (solid articles)
Water ReactivityMay ignite on contact with moisture or water; avoid water contact
ExtinguishingDry sand, dry chemical, soda ash; avoid water-based agents
PPE⚠️ Level B minimum; SCBA required; heat-resistant gloves recommended; avoid skin contact
IsolationERG 135: isolate spill area 25m in all directions; for large spills consider initial evacuation 100m in 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 3542 — Articles containing a substance liable t
HAZMAT RADIO NOTE — UN 3542 Product: Articles containing a substance liable to spontaneous combustion, n.o.s. Class 4 / Spontaneously Combustible / ERG 135 PPE: Level B minimum; SCBA required; heat-resistant gloves recommended; avoid skin contact ISOLATION: ERG 135: isolate spill area 25m in all directions; for large spills consider initial evacuation 100m in 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 3542 — Articles containing a substance liable to spontaneous combustion, n.o.s. Class: 4 | Placard: Spontaneously Combustible | ERG Guide: 135 Appearance: Variable appearance depending on the specific article and substance contained. Typically solid articles that contain materials capable of spontaneous ignition when exposed to air or moisture at ambient temperatures. Water Reactivity: May ignite on contact with moisture or water; avoid water contact Extinguishing: Dry sand, dry chemical, soda ash; avoid water-based agents PPE: Level B minimum; SCBA required; heat-resistant gloves recommended; avoid skin contact Isolation: ERG 135: isolate spill area 25m in all directions; for large spills consider initial evacuation 100m in 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/3542 | 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)
UN3542 Articles containing a substance liable to spontaneous combustion, n.o.s. Cls4 ERG135 | allfirefighter.com/hazmat/un/3542SMS / 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/3542
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; heat-resistant gloves recommended; avoid skin contact

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.