☣️ UN 3514 • CLASS 2
Adsorbed gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A)
Placard: Toxic Gas. 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 3514
Class: 2
Placard type: Toxic Gas
ERG: Guide 173 (check current ERG)
Isolation: ERG 173: Initial isolate 100m all directions; Protective Action Distance up to 5.0+ km downwind for large spills; evacuate immediately
Chemical & Response Details
| 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 |
| Extinguishing | Dry chemical, CO2; avoid water spray on container; foam not typically effective on gases |
| PPE | ⚠️ Level A required; positive-pressure SCBA mandatory; fully encapsulating chemical-protective suit; extreme inhalation hazard Zone A |
| Isolation | ERG 173: Initial isolate 100m all directions; Protective Action Distance up to 5.0+ km downwind for large spills; evacuate immediately |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Common hazards (high level)
- 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
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.
- Many gases are heavier than air and will spread along the ground and collect in low or confined areas
- 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.
Advertisement
📋 Copy & Share
UN 3514 — Adsorbed gas, poisonous, flammable, n.o. HAZMAT RADIO NOTE — UN 3514
Product: Adsorbed gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A)
Class 2 / Toxic Gas / ERG 173
PPE: Level A required; positive-pressure SCBA mandatory; fully encapsulating chemical-protective suit; extreme inhalation hazard Zone A
ISOLATION: ERG 173: Initial isolate 100m all directions; Protective Action Distance up to 5.0+ km downwind for large spills; evacuate immediately
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 3514 — Adsorbed gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A)
Class: 2 | Placard: Toxic Gas | ERG Guide: 173
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).
Water Reactivity: Variable depending on specific gas; may react violently or release toxic fumes when wet
Extinguishing: Dry chemical, CO2; avoid water spray on container; foam not typically effective on gases
PPE: Level A required; positive-pressure SCBA mandatory; fully encapsulating chemical-protective suit; extreme inhalation hazard Zone A
Isolation: ERG 173: Initial isolate 100m all directions; Protective Action Distance up to 5.0+ km downwind for large spills; evacuate immediately
— Key Hazards —
• TOXIC; may be fatal if inhaled or absorbed through skin.
• Vapors may be irritating.
• Contact with gas may cause burns and injury.
— 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.
• Many gases are heavier than air and will spread along the ground and collect in low or confined areas
SOURCE: allfirefighter.com/hazmat/un/3514 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief. Full chemical + response details.
UN3514 Adsorbed gas, poisonous, flammable, n.o.s. (Inhalation Hazard Zone A) Cls2 ERG173 | allfirefighter.com/hazmat/un/3514SMS / 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/3514
Advertisement
FAQ
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
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 A required; positive-pressure SCBA mandatory; fully encapsulating chemical-protective suit; extreme inhalation hazard Zone A
No. This is a training/quick-reference aid only. Always consult the current ERG Guide 173 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.