☣️ UN 3499 • CLASS 9

Capacitor, electric double layer

Placard: Miscellaneous. 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 3499
Class: 9
Placard type: Miscellaneous
ERG: Guide 171 (check current ERG)
Isolation: ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire involved, isolate 800m in all directions and consider initial evacuation for 800m
Chemical & Response Details
Also known asElectric double layer capacitorEDLCSupercapacitorUltracapacitorElectrochemical capacitor
AppearanceSolid device typically consisting of metal casing containing electrode materials, electrolyte solution, and separator membrane. May contain organic solvents or ionic liquids as electrolyte.
Flash PointNot applicable (assembled device)
Boiling PointNot applicable (assembled device)
Vapor DensityNot applicable (solid device)
Water ReactivityInternal electrolyte may react with water if device is damaged or breached; intact devices show no significant water reactivity
ExtinguishingDry chemical, CO2, sand, or water spray for external fires; avoid breaching device casing
PPE⚠️ Level D minimum for intact units; Level C with respiratory protection if damaged units release organic vapors or electrolyte
IsolationERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire involved, isolate 800m in all directions and consider initial evacuation for 800m
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
  • 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.
First actions (field-minded)
  • 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 3499 — Capacitor, electric double layer
HAZMAT RADIO NOTE — UN 3499 Product: Capacitor, electric double layer Class 9 / Miscellaneous / ERG 171 PPE: Level D minimum for intact units; Level C with respiratory protection if damaged units release organic vapors or electrolyte ISOLATION: ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire involved, isolate 800m in all directions and consider initial evacuation for 800m 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 3499 — Capacitor, electric double layer Class: 9 | Placard: Miscellaneous | ERG Guide: 171 Appearance: Solid device typically consisting of metal casing containing electrode materials, electrolyte solution, and separator membrane. May contain organic solvents or ionic liquids as electrolyte. Water Reactivity: Internal electrolyte may react with water if device is damaged or breached; intact devices show no significant water reactivity Extinguishing: Dry chemical, CO2, sand, or water spray for external fires; avoid breaching device casing PPE: Level D minimum for intact units; Level C with respiratory protection if damaged units release organic vapors or electrolyte Isolation: ERG 171: isolate spill or leak area immediately for at least 25m in all directions; if fire involved, isolate 800m in all directions and consider initial evacuation for 800m — 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/3499 | 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)
UN3499 Capacitor, electric double layer Cls9 ERG171 | allfirefighter.com/hazmat/un/3499SMS / 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/3499
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

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 minimum for intact units; Level C with respiratory protection if damaged units release organic vapors or electrolyte

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.