☣️ UN 3542 • CLASS 4
UN 3542 — Articles containing a substance liable to spontaneous combustion, n.o.s.
Placard: Spontaneously Combustible. ERG Guide 135. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
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⚠️ Verification required:
Broad or variable material category; verify exact product, SDS and shipping papers.
⚠️ 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 3542 is Articles containing a substance liable to spontaneous combustion, n.o.s., assigned to ERG Guide 135. This entry should be verified with shipping papers, labels and the SDS before responders commit to close-range action.
Hazard overview: Articles containing a substance liable to spontaneous combustion, n.o.s. has article-specific hazards that depend on the contained material. Damaged articles, heat, pressure, smoke or exposed contents may increase risk.
Response guidance: Use ERG Guide 135, isolate the area, keep people upwind and avoid incompatible agents. Keep water away unless incident command confirms it is safe for the specific material.
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UN 3542 Quick Details
UN 3542
Product name: Articles containing a substance liable to spontaneous combustion, n.o.s.
DOT Class: 4
Placard type: Spontaneously Combustible
ERG Guide: 135 (check current ERG)
Initial isolation: ERG 135: isolate spill area 25m in all directions; for large spills consider initial evacuation 100m in all directions
Common Hazards of UN 3542
- 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.
Chemical Identity & Physical Properties
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.
| Also known as | Self-heating articlesPyrophoric articlesSpontaneously combustible articlesArticles containing self-reactive substances |
| 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. |
| Flash Point | Not applicable (spontaneously combustible) |
| Boiling Point | Not applicable (articles/solids) |
| Vapor Density | Not applicable (solid articles) |
| Water Reactivity | May ignite on contact with moisture or water; avoid water contact |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3542
Extinguishing Media
Dry sand, dry chemical, soda ash; avoid water-based agents
PPE Requirements
⚠️ Level B minimum; SCBA required; heat-resistant gloves recommended; avoid skin contact
Level B minimum; SCBA required; heat-resistant gloves recommended; avoid skin contact. Select final PPE using ERG guidance, SDS, monitoring and incident command.
Isolation & Evacuation
ERG 135: isolate spill area 25m in all directions; for large spills consider initial evacuation 100m in all directions
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 135).
First Actions for a UN 3542 Incident
- 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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📋 Copy & Share Field Card
UN 3542 — Articles containing a substance liable tHAZMAT 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.
=== 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 —
• 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.
SOURCE: allfirefighter.com/hazmat/un/articles-containing-a-substance-un-3542 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN3542 Articles containing a substance liable to spontaneous combustion, n.o.s. Cls4 ERG135 | allfirefighter.com/hazmat/un/articles-containing-a-substance-un-3542SMS / 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/articles-containing-a-substance-un-3542
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Frequently Asked Questions about UN 3542
UN 3542 is Articles containing a substance liable to spontaneous combustion, n.o.s., assigned to ERG Guide 135.
ERG Guide 135 applies for initial isolation, protective actions and first response guidance.
Articles containing a substance liable to spontaneous combustion, n.
Level B minimum; SCBA required; heat-resistant gloves recommended; avoid skin contact.
ERG 135: isolate spill area 25m in all directions; for large spills consider initial evacuation 100m in all directions.
Water compatibility depends on the specific contents and incident conditions. Check ERG 135, SDS and incident command before applying water.
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.