☣️ UN 0493 • CLASS 1
Signals, railway track, explosive
Placard: Explosive 1.4G. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ 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.
Advertisement
Quick details
UN 0493
Class: 1
Placard type: Explosive 1.4G
ERG: Guide 114 (check current ERG)
Isolation: ERG 114: isolate 100m in all directions; if fire or explosion, isolate 800m and consider evacuation for 800m in all directions
Chemical & Response Details
| Also known as | Railway detonatorsTrack signalsTrack torpedoesRail warning signalsExplosive track devices |
| Appearance | Small metal or plastic cylindrical devices containing a small explosive charge designed to create a loud report when crushed by a train wheel. Typically wrapped in protective casing. |
| Flash Point | Not applicable (explosive device) |
| Boiling Point | Not applicable (explosive device) |
| Vapor Density | Not applicable (solid explosive device) |
| Water Reactivity | No significant reaction with water |
| Extinguishing | Water spray, dry chemical, CO2, or regular foam acceptable for small fires |
| PPE | ⚠️ Level C minimum for handling; structural firefighter PPE adequate for fire response; maintain distance from bulk quantities |
| Isolation | ERG 114: isolate 100m in all directions; if fire or explosion, isolate 800m and consider evacuation for 800m in all directions |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- Minor blast or fire hazard — limited effect.
- Localized burning or deflagration possible.
- Smoke and heat from burning.
- Low mass explosion risk under normal conditions.
First actions (field-minded)
- CALL 911. Notify law enforcement.
- Isolate area; keep unauthorized personnel away.
- Stage upwind; eliminate ignition sources.
- Request Hazmat + law enforcement.
- Consult current ERG Guide 114 and follow SOP/SOG.
Advertisement
📋 Copy & Share
UN 0493 — Signals, railway track, explosive HAZMAT RADIO NOTE — UN 0493
Product: Signals, railway track, explosive
Class 1 / Explosive 1.4G / ERG 114
PPE: Level C minimum for handling; structural firefighter PPE adequate for fire response; maintain distance from bulk quantities
ISOLATION: ERG 114: isolate 100m in all directions; if fire or explosion, isolate 800m and consider evacuation for 800m 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 0493 — Signals, railway track, explosive
Class: 1 | Placard: Explosive 1.4G | ERG Guide: 114
Appearance: Small metal or plastic cylindrical devices containing a small explosive charge designed to create a loud report when crushed by a train wheel. Typically wrapped in protective casing.
Water Reactivity: No significant reaction with water
Extinguishing: Water spray, dry chemical, CO2, or regular foam acceptable for small fires
PPE: Level C minimum for handling; structural firefighter PPE adequate for fire response; maintain distance from bulk quantities
Isolation: ERG 114: isolate 100m in all directions; if fire or explosion, isolate 800m and consider evacuation for 800m in all directions
— Key Hazards —
• Minor blast or fire hazard — limited effect.
• Localized burning or deflagration possible.
• Smoke and heat from burning.
— First Actions —
• CALL 911. Notify law enforcement.
• Isolate area; keep unauthorized personnel away.
• Stage upwind; eliminate ignition sources.
• Request Hazmat + law enforcement.
SOURCE: allfirefighter.com/hazmat/un/0493 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN0493 Signals, railway track, explosive Cls1 ERG114 | allfirefighter.com/hazmat/un/0493SMS / 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/0493
Related UN numbers (same class)
Discovery block for training / quick reference. Always consult the current ERG + your SOP/SOG for operations.
Advertisement
FAQ
Minor blast or fire hazard — limited effect. Localized burning or deflagration possible. Smoke and heat from burning. Low mass explosion risk under normal conditions.
CALL 911. Notify law enforcement. Isolate area; keep unauthorized personnel away. Stage upwind; eliminate ignition sources.
Level C minimum for handling; structural firefighter PPE adequate for fire response; maintain distance from bulk quantities
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 114 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.