UN 3514 — Adsorbed gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A)
Placard: Toxic Gas. ERG Guide 173. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
UN 3514 is Adsorbed gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A), a pressurized hazardous material assigned to ERG Guide 173. The exact contents should be verified from shipping papers and the SDS before close-range action.
Hazard overview: Primary hazards include toxic exposure, corrosive burns, fire or vapor ignition, container rupture. Adsorbed gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A) may release irritating, toxic or corrosive vapors when heated, spilled or involved in fire, so avoid contact, inhalation and incompatible materials.
Response guidance: For a UN 3514 incident, establish incident command, isolate the area, stay upwind and uphill, keep unauthorized personnel away, verify shipping papers/SDS and follow ERG 173. Use extinguishing, cooling, containment and decontamination tactics only when compatible with the material and local SOP.
UN 3514 Quick Details
Common Hazards of UN 3514
- TOXIC; may be fatal if inhaled or absorbed through skin.
- Vapors may be irritating.
- Contact with gas may cause burns and injury.
- Fire will produce irritating, corrosive and/or toxic gases.
- Runoff from fire control or dilution water may cause environmental contamination.
- Some gases may burn or be ignited by heat, sparks or flames.
- May form explosive mixtures with air.
- Oxidizers may ignite combustibles (wood, paper, oil, clothing, etc.) but NOT readily due to low
Chemical Identity & Physical Properties
Adsorbed compressed gas on porous solid material; color and odor vary depending on specific gas. Extremely toxic with high inhalation hazard (Zone A indicates LC50 ≤200 ppm).
| Also known as | Adsorbed toxic gas, flammable, n.o.s.Poisonous gas, adsorbed, flammable, n.o.s.Toxic flammable adsorbed gas, Zone AUN3514 adsorbed gas |
| Appearance | Adsorbed compressed gas on porous solid material; color and odor vary depending on specific gas. Extremely toxic with high inhalation hazard (Zone A indicates LC50 ≤200 ppm). |
| Flash Point | Not applicable (compressed/adsorbed flammable gas) |
| Boiling Point | Not applicable (varies by specific adsorbed gas component) |
| Vapor Density | Not applicable (adsorbed on solid substrate) |
| Water Reactivity | Variable depending on specific gas; may react violently or release toxic fumes when wet |
Fireground Response Guidance — UN 3514
Extinguishing Media
PPE Requirements
Level A required; positive-pressure SCBA mandatory; fully encapsulating chemical-protective suit; extreme inhalation hazard Zone A
Isolation & Evacuation
First Actions for a UN 3514 Incident
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area for at least 100 meters (330 feet) in all directions.
- See Table 1 - Initial Isolation and Protective Action Distances.
📋 Copy & Share Field Card
UN 3514 — Adsorbed gas, poisonous, flammable, n.o.Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
Use for: Quick text to command or incoming units. Fits in a single SMS.