☣️ UN 3508 • CLASS 9
UN 3508 — Capacitor, asymmetric
Placard: Miscellaneous. ERG Guide 171. 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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UN 3508 Quick Details
UN 3508
Product name: Capacitor, asymmetric
DOT Class: 9
Placard type: Miscellaneous
ERG Guide: 171 (check current ERG)
Initial isolation: ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire or explosion, isolate 800m and evacuate initial 800m in all directions
Common Hazards of UN 3508
- Some may burn but none ignite readily.
- Containers may explode when heated.
- Some may be transported hot.
- For UN3508, Capacitor, asymmetric, be aware of possible short circuiting as this product is transported
- Polymeric beads, expandable (UN2211) may evolve flammable vapours.
- Inhalation of material may be harmful.
- Contact may cause burns to skin and eyes.
- Inhalation of Asbestos dust may have a damaging effect on the lungs.
Chemical Identity & Physical Properties
| Also known as | Asymmetric capacitorElectrochemical capacitorSupercapacitorUltracapacitor |
| Appearance | Solid electronic component, typically cylindrical or rectangular sealed unit containing electrolyte and electrodes. May contain organic electrolytes and activated carbon materials. |
| Flash Point | Not applicable (sealed electronic device) |
| Boiling Point | Not applicable (sealed electronic device) |
| Vapor Density | Not applicable (solid device) |
| Water Reactivity | No significant reaction when intact; damaged units may release electrolyte that reacts with water |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 3508
Extinguishing Media
Dry chemical, CO2, water spray for cooling; avoid direct water on damaged units
PPE Requirements
⚠️ Level D for intact units; Level C with chemical gloves if damaged units release electrolyte; respiratory protection if thermal runaway occurs
Isolation & Evacuation
ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire or explosion, isolate 800m and evacuate initial 800m in all directions
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 171).
First Actions for a UN 3508 Incident
- CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- 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 3508 — Capacitor, asymmetricHAZMAT RADIO NOTE — UN 3508
Product: Capacitor, asymmetric
Class 9 / Miscellaneous / ERG 171
PPE: Level D for intact units; Level C with chemical gloves if damaged units release electrolyte; respiratory protection if thermal runaway occurs
ISOLATION: ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire or explosion, isolate 800m and evacuate initial 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 3508 — Capacitor, asymmetric
Class: 9 | Placard: Miscellaneous | ERG Guide: 171
Appearance: Solid electronic component, typically cylindrical or rectangular sealed unit containing electrolyte and electrodes. May contain organic electrolytes and activated carbon materials.
Water Reactivity: No significant reaction when intact; damaged units may release electrolyte that reacts with water
Extinguishing: Dry chemical, CO2, water spray for cooling; avoid direct water on damaged units
PPE: Level D for intact units; Level C with chemical gloves if damaged units release electrolyte; respiratory protection if thermal runaway occurs
Isolation: ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire or explosion, isolate 800m and evacuate initial 800m in all directions
— Key Hazards —
• Some may burn but none ignite readily.
• Containers may explode when heated.
• Some may be transported hot.
— First Actions —
• CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• 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/3508 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3508 Capacitor, asymmetric Cls9 ERG171 | ERG 171: isolate spill or leak area immediately for at least 25m in all directio | allfirefighter.com/hazmat/un/3508SMS / 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/3508
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Frequently Asked Questions about UN 3508
Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, Capacitor, asymmetric, be aware of possible short circuiting as this product is transported Polymeric beads, expandable (UN2211) may evolve flammable vapours. Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs.
CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper Keep unauthorized personnel away. Stay upwind, uphill and/or upstream.
Level D for intact units; Level C with chemical gloves if damaged units release electrolyte; respiratory protection if thermal runaway occurs
Water reactivity: No significant reaction when intact; damaged units may release electrolyte that reacts with water. Recommended extinguishing: Dry chemical, CO2, water spray for cooling; avoid direct water on damaged units.
ERG Guide 171 recommendation: ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire or explosion, isolate 800m and evacuate initial 800m in all directions
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 171 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.